# GCN_circulars

GRB_name: GRB081016B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8382
SUBJECT: GRB 081016B: ROTSE-III Optical Limits
DATE:    08/10/16 20:14:33 GMT
FROM:    Brad Schaefer at LSU  <schaefer@grb.phys.lsu.edu>

B. E. Schaefer (Louisiana State), E.S. Rykoff (UCSB), and H. Swan (U.  
Mich.) report on behalf of the ROTSE collaboration:

ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, 
responded to GRB 081016B (Swift trigger 331856), producing images 
beginning 6.4 s after the GCN notice time. An automated response took the 
first image at 19:47:59.4 UT, 44.9 s after the burst, under excellent 
conditions. We took 10 5-sec, 10 20-sec and 20 60-sec exposures. These 
unfiltered images are calibrated relative to USNO A2.0 (R). Imaging is on 
going.

Comparison to the DSS (second epoch) reveals no new sources within the 
3-sigma Swift/BAT error circle or the XRT error circle, for both single 
images and coadding into sets of 10; the field is not crowded. Individual 
images have limiting magnitudes ranging from 15.8-17.1; we set the 
following specific limits.

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
19:47:59.4   19:48:04.4         5     15.8           44.9       N
19:47:59.4   19:49:15.5        76     17.5           44.9       Y

[GCN OPS NOTE(17oct08): Per author's request, the burst name was changed
from "A" to "B".]


GRB_name: GRB081016B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8383
SUBJECT: GRB 081016B: Enhanced Swift-XRT position
DATE:    08/10/17 00:40:37 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2096 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 081016B, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 14.56434, -43.53015 which is equivalent
to:

RA (J2000): 00h 58m 15.44s
Dec (J2000): -43d 31' 48.5"

with an uncertainty of 2.1 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081016B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8384
SUBJECT: GRB 081016B: Swift-XRT Team refined Analysis 
DATE:    08/10/17 05:10:42 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

K.L. Page (U. Leicester) reports on behalf of the Swift-XRT team:

We have analysed the first six orbits of the XRT data obtained for GRB 
081016B (Page et al., GCN Circ. 8381). After an initial 18 seconds in 
Windowed Timing mode, the remaining 3.5 ks were collected in Photon 
Counting (PC) mode. The UVOT-enhanced position was given by Osborne et al. 
in GCN Circ. 8383.

The first orbit of data shows a decay of alpha = 1.1 +/- 0.3. However, 
after the end of this orbit (~265 s after the trigger), the source is no 
longer detected, indicating a break to a significantly steeper decay 
occurred.

The spectrum of the first orbit of PC data can be modelled with a 
power-law (Gamma = 1.20 +/- 0.18) absorbed at the Galactic value of NH = 
1.96x10^20 cm^-2. The upper limit on the total absorbing column is 
2.2x10^21 cm^-2. The observed (unabsorbed) flux over this time is 
2.43x10^-10 (2.48x10^-10) erg cm^-2 s^-1, corresponding to a counts to 
observed flux conversion of 6.8x10^-11 erg cm^-2 count^-1.

Because of the lack of detection after the first orbit, we cannot 
predict the future count rate.

This is an official product of the Swift-XRT team.


GRB_name: GRB081011A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8385
SUBJECT: GRB 081011: Swift XRT refined analysis
DATE:    08/10/17 14:10:54 GMT
FROM:    Dirk Grupe at PSU/Swift-XRT  <grupe@astro.psu.edu>

Dirk Grupe (PSU)  reports on behalf of the Swift-XRT team:


The XRT began observing the field of GRB 081011 (trigger=331332; Grupe 
et al.,
GCN Circ 8355) on 2008 October 11 00:30:24.4 UT, 93.9 s after
the BAT trigger.

The enhanced XRT position given in GCN Circ 8380 (Goad et al.)
is 59.3" away from the ground-processed BAT position given in GCN Circ. 
8357
(Sakamoto et al.),  consistent with that position. This position was
outside the central 200x200 pixel XRT window which is telemetered as 
SPER data,
hence the non-detection reported in GCN 8357.


The 0.3-10 keV X-ray light curve starts at a level of 7e-11 ergs/s/cm2 (1.8
counts/s) in the XRT with a steep decay slope at these early times of
alpha1 = 1.10+/-0.23 The light curve breaks at about 4+/-2 ks after the 
burst
and flattens to alpha2 = 0.24+/-0.17. Due to the proximity to the sun
constraint, it was decided to cancel the observations after the
first day. No further observations are planned and possible due the sun
constraint.


The spectrum of the Photon Counting mode data
can be fitted by an absorbed single powerlaw with a photon
index Gamma = 2.04 +/- 0.13 and column density fixed to the Galactic 
value of
1.04e20 cm-2 in the direction of the burst. The count rate to observed flux
conversion factor is 2.2e-11 (ergs/s/cm2)/(counts/s) in the 0.3-10 keV 
band.


This Circular is an official product of the Swift-XRT team.


GRB_name: GRB081016B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8386
SUBJECT: GRB 081016B: Swift/UVOT Upper Limits
DATE:    08/10/17 15:47:39 GMT
FROM:    Wayne Landsman at GSFC/SSAI  <wayne.b.landsman@nasa.gov>

W.Landsman (GSFC) and K. L. Page (U Leicester), on behalf of the 
Swift/UVOT team.

The Swift Ultra-Violet/Optical Telescope (UVOT) began settled 
observations of GRB 081016B (trigger 331856) 93 seconds after the BAT 
trigger (Page et al.,GCN Circ. 8381). No afterglow is detected at the 
enhanced XRT position (Osborne et al., GCN Circ. 8383) in the initial 
white finding chart or subsequent images. The limiting magnitudes 
(3-sigma in 3" radius 
apertures) in each of the UVOT filters are as follows:

Filter  T_start(s)  T_stop(s)  Exp(s)  Mag UL (3sig)

white       93       243       150     >21.5
b         4710      4823       113     >20.6
v         5373      5572       197     >20.0
u         5988     11724       960     >21.5
uvw1      5783      5982       197     >20.3
uvm2      5577      5777       197     >20.0
uvw2      5168      5368       197     >20.3

The values quoted above are in the UVOT photometric system (Poole et al. 
2008, MNRAS, 383, 627).  They are not corrected for the expected 
Galactic extinction corresponding to a reddening of E(B-V)=0.01 mag in 
the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB081016B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8387
SUBJECT: GRB 081016B, Swift-BAT refined analysis
DATE:    08/10/17 21:37:05 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm@nasa.gov>

M. Stamatikos (GSFC/ORAU), S. D. Barthelmy (GSFC), W. H. Baumgartner 
(GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),
K. L. Page (U Leicester),D. M. Palmer (LANL), A. M. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), J. Tueller (GSFC),
T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry 
downlink,
we report further analysis of BAT GRB 081016B (trigger #331856)
(Page, et al., GCN Circ. 8381).  The BAT ground-calculated position is
RA, Dec = 14.582, -43.536 deg which is
  RA(J2000)  =  00h 58m 19.8s
  Dec(J2000) = -43d 32' 07.9"
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 98%.

The BAT mask-weighted light curve showed a single peak of duration ~2.5 
seconds.
T90 (15-350 keV) is 2.6 +- 0.8 sec (estimated error including systematics).

The time-averaged spectrum from T-0.0 to T+3.0 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
0.92 +- 0.32.  The fluence in the 15-150 keV band is 9.9 +- 1.8 x 10-08 
erg/cm2.
The 1-sec peak photon flux measured from T+0.50 sec in the 15-150 keV band
is 0.5 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/331856/BA/


GRB_name: GRB081017A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8388
SUBJECT: GRB 081017: Swift detection of a burst
DATE:    08/10/17 23:52:01 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

O. Godet (U Leicester), S. D. Barthelmy (GSFC),
P. A. Evans (U Leicester), S. T. Holland (CRESST/USRA/GSFC),
J. A. Kennea (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL),
M. Stamatikos (NASA/ORAU), T. N. Ukwatta (GSFC/GWU) and
L. Vetere (PSU) report on behalf of the Swift Team:

At 23:38:12 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081017 (trigger=331964).  This was too close to the Sun
for Swift to slew to.  The BAT on-board calculated location is 
RA, Dec 230.180, -32.815 which is 
   RA(J2000) = 15h 20m 43s
   Dec(J2000) = -32d 48' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  As is usual for an image trigger, the immediately
available BAT light curve shows no obvious variation. 

Due to an observing constraint, Swift cannot slew to the BAT position. 
There will thus be no XRT or UVOT data for this trigger. 

Burst Advocate for this burst is O. Godet (og19 AT star.le.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081017A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8389
SUBJECT: GRB 081017: REM early observations
DATE:    08/10/18 00:41:20 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo, S. Covino, L.A. Antonelli, D. Malesani, D. Fugazza, L.  
Calzoletti,  S. Campana, G.  Chincarini, M.L. Conciatore, S. Cutini, V. 
D'Elia,  F. D'Alessio, F.  Fiore, P. Goldoni, D. Guetta,  C. Guidorzi, 
G.L. Israel, E. Maiorano, N. Masetti, A. Melandri, E. Meurs, L. 
Nicastro, E. Palazzi, E. Pian, S. Piranomonte, L.  Stella, G.  Stratta, 
G. Tagliaferri, G. Tosti, V.Testa, S.D. Vergani, F. Vitali report on 
behalf of the REM team:

The robotic 60-cm REM telescope located at La Silla (Chile) observed 
automatically the field of the GRB 081017 (Godet et al. GCN 8388) on Oct 
17 starting about 6.5 min after the burst.  Observations were carried 
out at high airmass. In a series of 10s and 30s exposures, at we do not 
see the any clear afterglow candidate inside the BAT error box down to R 
 > 17.0 and H > 15.5 (3sigma c.l.).


GRB_name: GRB081017A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8390
SUBJECT: GRB 081017, Swift-BAT refined analysis
DATE:    08/10/18 13:56:26 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

J. Tueller (GSFC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
O. Godet (U Leicester), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD),
D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 081017 (trigger #331964)
(Godet, et al., GCN Circ. 8388).  The BAT ground-calculated position is
RA, Dec = 230.209, -32.790 deg which is 
   RA(J2000)  =  15h 20m 50.1s 
   Dec(J2000) = -32d 47' 23.3" 
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 80%.
 
The mask-weighted light curve shows a broad lo-level emission with some
structure starting at ~T-70 and ending around T+400 sec.  The spacecraft slewed
to the next pre-planned observing target at T+400 sec such that the partial coding
of this burst location decreased to a small value.  As such the statisitical
error on the flux measurement increased to the point that we can only say
there is a hint of emission out to around T+700 sec.
T90 (15-350 keV) is 320 +- 50 sec (estimated error including systematics).
 
The time-averaged spectrum from T+0.0 to T+320.0 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.64 +- 0.23.  The fluence in the 15-150 keV band is 1.4 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.00 sec in the 15-150 keV band
is 0.07 +- 0.01 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/331964/BA/


GRB_name: GRB081012A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8391
SUBJECT: GRB 081012 - Enhanced Swift XRT position
DATE:    08/10/20 15:53:53 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team:

Using 1387 s of XRT Photon Counting mode data and 2 UVOT images, we find 
an astrometrically corrected X-ray position (using the XRT-UVOT alignment 
and matching to the USNO-B1 catalogue): RA, Dec = 30.2009, -17.6383 which 
is equivalent to:

RA (J2000): 02 00 48.22
Dec (J2000): -17 38 18.0

with an uncertainty of 1.8 arcsec (90% confidence).

This position may be improved as more data are received. The latest 
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position 
enhancement is described by Goad et al. (2007, A&A, 476, 1401 
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is 
an extension of this method. 

This circular is an offical product of the Swift XRT team.


GRB_name: GRB081012A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8394
SUBJECT: GRB 081012: Swift-XRT Refined Analysis
DATE:    08/10/21 21:48:38 GMT
FROM:    Michael Stroh at PSU/Swift  <stroh@astroh.org>

M.C. Stroh and C. Pagani (PSU) report on behalf of the Swift-XRT team:

We have analyzed the Swift-XRT data obtained for GRB 081012 (Stroh et  
al., GCN Circ. 8361), totaling 30.4ks of Photon Counting data.

The X-ray light-curve can be fit by a simple power law with a decay  
index of 1.49 +/- 0.07.

The spectrum can be fit with an absorbed power-law with absorption  
consistent with the Galactic nH value (2.37e20 cm-2, Kalberla et al.  
2005) and with a photon index of 1.44 (+0.35/-0.34). The average  
observed (unabsorbed) 0.3-10 keV flux is 6.19e-11 (6.40e-11) ergs/cm^2/ 
s.

This is an official product of the Swift-XRT team.


GRB_name: GRB081022A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8395
SUBJECT: GRB 081022: Swift detection of a burst
DATE:    08/10/22 14:39:25 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@astro.psu.edu>

G. Stratta (ASDC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), P. A. Evans (U Leicester),
N. Gehrels (NASA/GSFC), C. Guidorzi (INAF-OAB),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
J. A. Kennea (PSU), J. Mao (INAF-OAB),
C. B. Markwardt (CRESST/GSFC/UMD), P. T. O'Brien (U Leicester),
J. P. Osborne (U Leicester), K. L. Page (U Leicester),
M. Perri (ASDC), B. Preger (ASDC), P. Romano (INAF-IASFPA),
B. Sbarufatti (INAF-IASFPA), M. Stamatikos (NASA/ORAU),
L. Vetere (PSU) and H. Ziaeepour (UCL-MSSL) report on behalf of the
Swift Team:

At 14:23:48 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081022 (trigger=332399). 
The BAT on-board calculated location is 
RA, Dec 226.619, +12.416 which is 
   RA(J2000) = 15h 06m 28s
   Dec(J2000) = +12d 24' 58"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  This was an image trigger in BAT, but the 
light curve shows a long, smooth, 100 second wide peak with a maximum 
of ~500 cts/sec at T+50 seconds. 

Due to an observing constraint, Swift cannot slew to the BAT position. 
There will thus be no XRT or UVOT data for this trigger. 

Burst Advocate for this burst is G. Stratta (giulia.stratta AT asdc.asi.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081016A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8396
SUBJECT: GRB 081016A: Swift-XRT refined analysis
DATE:    08/10/22 14:45:09 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:

Swift-XRT reobserved the field of the INTEGRAL GRB 081016A (Gotz  et al.
GCN Circ. 8377) 5.2 days after the trigger, obtaining 3.8 ks of data in
Photon Counting (PC) mode. The source seen in the earlier XRT
observation (Evans, GCN Circ. 8379) was no longer detected. A
three-sigma upper limit on the count rate is 4.7e-3 counts/sec,
significantly below the level of the previous detection (0.03
counts/sec). We therefore confirm that this was the afterglow of
GRB 081016A.

A spectrum formed from the first XRT observation, totalling 2 ks in PC
mode, can be modelled with an absorbed power law with photon index
2.60 (+0.94, -0.81). The absorption column is consistent with the
Galactic value of 1.7e21 cm^-2 (Kalberla et al 2005). The counts to
observed (unabsorbed) flux conversion factor is 1.1e-12 (3.0e-12) erg
cm^-2 ct^-1.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081022A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8397
SUBJECT: GRB 081022, Swift-BAT refined analysis
DATE:    08/10/22 20:41:45 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

T. N. Ukwatta (GWU) S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
G. Stratta (ASDC), J. Tueller (GSFC)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+903 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 081022 (trigger #332399)
(Stratta, et al., GCN Circ. 8395).  The BAT ground-calculated position is
RA, Dec = 226.584, 12.409 deg which is 
   RA(J2000)  =  15h 06m 20.1s 
   Dec(J2000) = +12d 24' 32.7" 
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 64%.
 
The mask-weighted light curve shows a long smooth peak starting at ~T-10 sec,
peaking around T+50 sec, and ending around T+210 sec.
T90 (15-350 keV) is 160 +- 40 sec (estimated error including systematics).
 
The time-averaged spectrum from T-9.3 to T+207.3 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.67 +- 0.11.  The fluence in the 15-150 keV band is 2.5 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+57.18 sec in the 15-150 keV band
is 0.6 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/332399/BA/


GRB_name: GRB081024A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8398
SUBJECT: GRB 081024: Swift detection of a burst
DATE:    08/10/24 06:18:55 GMT
FROM:    Neil Gehrels at GSFC  <gehrels@milkyway.gsfc.nasa.gov>

G. Stratta (ASDC), W. H. Baumgartner (GSFC/UMBC),
N. Gehrels (NASA/GSFC), E. A. Hoversten (PSU),
C. B. Markwardt (CRESST/GSFC/UMD), M. Perri (ASDC) and
L. Vetere (PSU) report on behalf of the Swift Team:

At 05:53:08 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081024 (trigger=332516).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 27.898, +61.346 which is 
   RA(J2000) = 01h 51m 36s
   Dec(J2000) = +61d 20' 47"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a short hard peak with 
a duration of about 0.3 sec at T+0 with a short precursor peak at T-2.5 seconds. 
The peak count rate was ~6,000 counts/sec (15-350 keV), at ~0 sec after
the trigger. 

The XRT began observing the field at 05:54:21.1 UT, 72.3 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 27.8745,
61.3317 which is equivalent to:
   RA(J2000)  = 01h 51m 29.88s
   Dec(J2000) = +61d 19' 54.1"
with an uncertainty of 2.3 arcseconds (radius, 90% containment). This
location is 65 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
7.71e+21 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of nominal 150 seconds with the White
(160-650 nm) filter starting 76 seconds after the BAT trigger. No afterglow
candidate has been found in the initial data products. Image catalog data are
not available at this time. The 8'x8' region for the list of sources generated
on-board covers 100% of the BAT error circle. The list of sources is typically
complete to about 18 mag. No correction has been made for the large, but
uncertain extinction expected. 

This appears to be a short hard GRB with a precursor and a fading X-ray 
afterglow.  We note that the position in galactic coordinates is l=130deg, 
b=-0.7 deg.  It is not impossible that this is a galactic transient or
even an SGR. 

Burst Advocate for this burst is G. Stratta (giulia.stratta AT asdc.asi.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081024A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8399
SUBJECT: GRB 081024A: ROTSE-III Optical Limits
DATE:    08/10/24 06:33:52 GMT
FROM:    Brad Schaefer at LSU  <schaefer@grb.phys.lsu.edu>

B. E. Schaefer (Louisiana State), E.S. Rykoff (UCSB), H. Swan (U Mich), W. 
Rujopakarn (Steward), report on behalf of the ROTSE collaboration:

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 
081024A (Swift trigger 332516; G. Stratta, GCN 8398), producing images 
beginning 9.1 s after the GCN notice time. An automated response took the 
first image at 05:53:37.2 UT, 28.4 s after the burst, under excellent 
conditions. We took 10 5-sec, 10 20-sec and 40 60-sec exposures. These 
unfiltered images are calibrated relative to USNO A2.0 (R). Imaging is on 
going.

Comparison to the DSS (second epoch) reveals no new sources within the 
3-sigma Swift/BAT error circle or the XRT error circle, for both single 
images and coadding into sets of 10; however, we are limited as the field 
is somewhat crowded. Individual images have limiting magnitudes ranging 
from 16.1-17.1; we set the following specific limits.

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
05:53:37.1   05:53:42.1         5     16.2           28.3       N
05:54:57.0   05:59:37.7       280     17.2          108.2       Y


GRB_name: GRB081024A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8400
SUBJECT: GRB 081024: Early Super-LOTIS Observations
DATE:    08/10/24 08:10:37 GMT
FROM:    Grant Williams at Steward Observatory  <ggwilli@gmail.com>

G. G. Williams (MMTO) and P. A. Milne (Steward Observatory), on behalf
of the Super-LOTIS Collaboration, report:

The robotic 0.6-m Super-LOTIS telescope began observing the error box
of GRB 081024 (Swift Trigger 332516, Stratta et al. GCN 8398) at
05:53:49.9 UT, 41.9 seconds after the trigger.  Our initial
observations include 5 x 10s exposures, 5 x 20s exposures, and 30 x
60s exposures, all in the R-band.

We do not detect any variable sources or afterglow candidates within
the XRT error box in our earliest exposure to the following 3-sigma
limiting magnitude determined from the nearby USNO-B1.0 star
1513-0063175 with R2=14.24:

t_start (UT) exp t (s) t_start-t_0 (s) Limit
------------------------------------------------------------
05:53:49.9 10   41.9   R > 17.6

The value quoted above is not corrected for the expected Galactic
extinction corresponding to a reddening of E(B-V)=1.64 mag in the
direction of the burst (Schlegel et al. 1998).

Additional observations and analysis are ongoing.


GRB_name: GRB081024A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8401
SUBJECT: GRB 081024: KAIT Optical Limits
DATE:    08/10/24 08:16:22 GMT
FROM:    Weidong Li at UC Berkeley KAIT/LOSS  <weidong@astron.berkeley.edu>

W. Li, R. Chornock, and A. V. Filippenko, University of California
at Berkeley, on behalf of the KAIT GRB team, report:

The robotic 0.8-m KAIT located at Lick Observatory responded to
GRB 081024 (G. Stratta, GCN 8398) automatically and started
the first image at 05:54:42 UT (94 seconds after the burst).
A series of images were taken in the V, I, and clear filters.
No new sources were detected within the Swift/XRT error circle
in the KAIT images (single or stacked frames) when compared to
the DSS II. We set the following specific limiting magnitude 
in a stacked unfiltered image (2s x 10; USNO B1 calibration): 

start UT       end UT      t_exp(s)   mlim 
--------------------------------------------
05:54:42.0   05:55:16.0        20     18.8  


GRB_name: GRB081024A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8402
SUBJECT: GRB 081024: Faulkes Telescope North optical observations
DATE:    08/10/24 10:56:02 GMT
FROM:    Andrea Melandri at Liverpool John Moores U  <axm@astro.livjm.ac.uk>

A. Melandri, M. Burgdorf, R.J. Smith, I.A. Steele, D.F. Bersier,
C.G. Mundell, (Liverpool JMU), A. Gomboc (Ljubljana), C. Guidorzi
(INAF-OAB) on behalf of a larger collaboration report:


On 2008 October 24 at 05:54:45 UT (~50 seconds after the GRB trigger)
we observed the field of GRB 081024 (trigger = 332516, Stratta et al.,
GCN 8938) with the robotic 2m Faulkes Telescope North located in
Hawaii.

Observations were performed on BVRi filters. We do not detect any
fadind optical source within the XRT error circle (Stratta et al.,
GCN 8938) down to the following limits:


--------------------------------------------------
  Dt_mid    T_exp     Filter      Mag_lim
   [min]    [sec]
--------------------------------------------------
   2.25      30         R         > 21.4
  112.8     600         R         > 22.6
  136.2     600         I         > 21.2
--------------------------------------------------


Limiting magnitudes has been estimated using the R2 and I magnitudes
of the USNOB-1 catalogue. The reported values are not corrected for
the Galactic extinction.


GRB_name: GRB081024A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8403
SUBJECT: GRB 081024: Enhanced Swift-XRT position
DATE:    08/10/24 11:53:14 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 1443 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 081024, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 27.8738, +61.3314 which is equivalent
to:

RA (J2000): 01h 51m 29.72s
Dec (J2000): +61d 19' 53.0"

with an uncertainty of 1.9 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081024A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8404
SUBJECT: GRB 081024, Swift-BAT refined analysis 
DATE:    08/10/24 14:51:55 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <jayc@milkyway.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),
D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), G. Stratta (ASDC),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 081024 (trigger #332516)
(Stratta, et al., GCN Circ. 8398).  The BAT ground-calculated position is
RA, Dec = 27.891, 61.352 deg which is
  RA(J2000)  =  01h 51m 33.8s
  Dec(J2000) = +61d 21' 08.2"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
This position is 1.3 arcmin from the enhanced XRT position (Beardmore et
al. GCN Circ. 8403).  The partial coding was 97%.

The mask-weighted lightcurve shows a slightly softer precursor peak about
0.05 sec long at T-1.7 sec, a peak about 0.3 seconds long at T-0.2 sec and
the largest peak 0.1 seconds long at T0.  T90 (15-350 keV) is 1.8 +- 0.6 
sec
(estimated error including systematics).

The time-averaged spectrum from T-1.7 to T+0.3 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.23 +- 0.21.  The fluence in the 15-150 keV band is
1.2 +- 0.2 x 10-07 erg/cm2.  The 1-sec peak photon flux measured from
T-0.73 sec in the 15-150 keV band is 1.1 +- 0.1 ph/cm2/sec.  All the quoted
errors are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/332516/BA/


GRB_name: GRB081024A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8405
SUBJECT: GRB 081024: Swift-XRT refined analysis
DATE:    08/10/24 20:31:08 GMT
FROM:    Matteo Perri at ISAC/ASDC  <perri@asdc.asi.it>

G. Stratta (ASDC) reports on behalf of the Swift-XRT team:

We have analysed the first orbit of the XRT data obtained for
GRB 081024 (Stratta et al., GCN Circ. 8398). From T+78 s to T+105 s
after the burst, data were collected in Windowed Timing mode and
then XRT switched to Photon Counting mode. The Enhanced Swift-XRT
position was given by Beardmore et al. in GCN Circ. 8403.

The 0.3-10 keV flux from T+78 s to T+355 s shows a very steep decay with
a possible small re-brightening between ~T+145 s to ~T+205 s. Excluding
the re-brightening and assuming a power law decay, the best fit decay
index is alpha = 3.7 (+0.8,-0.5).

The spectrum of the WT data, with an integration time of 27s, can
be modelled with a power-law model with photon index of 1.6 (+0.6,- 0.3).
The total absorbing equivalent hydrogen column density is consistent
with the Galactic one NH = 7.71E+21 cm^-2 (Kalberla et al. 2005). The
observed (unabsorbed) 0.3-10 keV flux is 4.1(6.1)E-10 erg/cm^-2 s^-1

No source counts are detected after the first orbit, likely due to
the very steep flux decay.

This is an official product of the Swift-XRT team.


GRB_name: GRB081024A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8406
SUBJECT: Swift UVOT observations of GRB 081024
DATE:    08/10/25 11:53:56 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps@mssl.ucl.ac.uk>

M. De Pasquale (MSSL/UCL) and G. Stratta (ASDC) report on behalf of  
the Swift UVOT team.

The Swift UltraViolet/Optical Telescope (UVOT) began its finding chart  
exposure of GRB081024 (Swift BAT trigger
number 332516, Stratta et al., GCN Circ. 8398), 77s after the trigger.

We do not detect any new source at the XRT position reported in GCN  
Circ. 8403 (Beardmore et al.) either
in the finding chart nor in in successive coadded observations.

The magnitude 3 sigma upper limits for detecting GRB081024 at the XRT  
position are given below.

  Filter  Tstart(s)  Tstop(s)  Exp(s)  Magnitude
  wh        77          227        147        >20.8
  wh        516       13395     1258      >22.0
  v           565       758         39          >18.5
  v           1041     7298       490        >19.9
  b           491       856         58          >19.6
  b           1140     12771     1358      >21.4
  u           235       485         250        >20.1
  u           639       11859     807        >21.0
  uvw1     615       7615      436        >20.2
  uvm2     590       7503      529        >20.5
  uvw2     541       7093      529        >20.6


  The values quoted above are on the UVOT Photometric System (Poole et  
al, 2008, MNRAS 383,627). They are not
corrected for the unknown but expected large Galactic extinction in  
the direction of this burst.


GRB_name: GRB081024B
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8407
SUBJECT: Fermi-LAT observation of GRB 081024B 
DATE:    08/10/25 14:07:58 GMT
FROM:    Nicola Omodei at INFN(Pisa)/GLAST  <nicola.omodei@pi.infn.it>

Nicola Omodei (INFN Pisa),
on behalf of the Fermi-LAT Collaboration

The Fermi LAT telescope detected an increased count rate at 2008/10/24 
(21:22:41),
associated with a GRB detected also by the Fermi GBM (Trigger 
number:246576161).
The location of the GRB reported by Fermi LAT data ground analysis is:
Ra=322.9, Dec=21.204
which corresponds to
Ra (J2000) = 21:31:36.00
Dec (J200) = 21:12:14.4
within a statistical uncertainty of 0.16 degrees (68% containment radius).
The emission from this point source was seen up to 3 GeV, in the first 5 
seconds after the trigger.

The Fermi LAT point of contact for this burst is Nicola Omodei 
(nicola.omodei@pi.infn.it).

The Fermi LAT is a pair conversion telescope designed to cover the 
energy band from 20 MeV to greater than 300 GeV.
It is the product of an international collaboration between NASA and DOE 
in the U.S. and many scientific institutions across France, Italy, Japan 
and Sweden.
This message can be cited.


GRB_name: GRB081024B
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8408
SUBJECT: GRB 081024B:  Fermi Gamma-ray Burst Monitor detection
DATE:    08/10/25 19:00:20 GMT
FROM:    Valerie Connaughton at MSFC  <valerie@nasa.gov>

Valerie Connaughton and Michael Briggs (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 21:22:40.86 UT on 24 October 2008, the Fermi Gammay-Ray Burst
Monitor (GBM) triggered on GRB 081024B (trigger 246576161 /
081024.891). The calculated location is consistent with the
Fermi LAT-detected GRB reported by N. Omodei in GCN Circular 8407.

This GRB was about 800 ms long with 2 main peaks.  The first peak
lasted 200 ms and its spectrum is best fit using a power-law index
with an exponential cutoff.  The power-law index is -0.70  0.13, and
the cutoff energy, parameterized as EPeak, is 1583  520 keV. The
seond peak lasted 600 ms and is best fit by a power-law spectrum
with an index of -1.28  0.04.

The fluence between 50 and 300 keV of this short burst is
3.4  0.1 x 10-7 erg/cm2, with a peak flux measured over
a 64 ms timescale of of 4.2  0.2 photons/cm2/sec.  Between
15 and 150 keV the 64 ms peak flux is 7.4  0.4 photons/cm2/sec.

The analysis results presented above are preliminary and further
analysis is being performed; the final results will be published
in the GBM GRB Catalog."


GRB_name: GRB081025A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8409
SUBJECT: GRB 081025: Burst detection from Swift-BAT slew data
DATE:    08/10/26 01:18:16 GMT
FROM:    Antonio Copete at Harvard U  <acopete@head.cfa.harvard.edu>

A. Copete, J. Grindlay (Harvard)
J. Cummings, S. Barthelmy, C. Markwardt, N. Gehrels (NASA/GSFC)

We report the detection of a GRB candidate by the BAT Slew Survey  
(BATSS) in the slew that started at 08:22:02 UT. The ground-calculated  
position is
RA, Dec = 245.298 +60.466 deg, which is
  RA (J2000) =  16h 21m 11s
  Dec(J2000) = +60d 27' 58"
with an uncertainty of 2.87 arcmin (90% confidence, including  
systematic error). The detection was triggered by simultaneous  
independent detections of 12.9 sigma and 13.7 sigma from imaging in  
the 15-50 keV and 50-150 keV energy bands, respectively. The burst  
profile shows a series of 4 main peaks starting at T+63sec, which a  
measured T90 = 23sec and T50 = 17sec, and the burst leaves the BAT  
field-of-view at T+120.

A follow-up Swift ToO observation has been scheduled to begin on  
10/26/08 at 04:58 UT, 20.6 hours after the burst.


GRB_name: GRB081024B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8410
SUBJECT: GRB 081024B: Swift-XRT observations
DATE:    08/10/26 10:43:34 GMT
FROM:    Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>

C. Guidorzi, R. Margutti, J. Mao (INAF-OAB) report on behalf of
the Swift-XRT team:

Swift began observing the field of the Fermi-LAT GRB 081024B (Omodei et
al., GCN Circ. 8407) 70.3 ks after the trigger. In 9.9 ks of Photon
Counting mode data, we detect three uncatalogued sources within the
Fermi-LAT error circle at the following positions:

Source 1:
RA(J2000):   21 31 47.85
Dec(J2000): +21 08 33.7
with an uncertainty of 6.6 arcsec.

Source 2:
RA(J2000):   21 31 37.22
Dec(J2000): +21 16 32.1
with an uncertainty of 5.4 arcsec.

Source 3:
RA(J2000):   21 31 29.26
Dec(J2000): +21 16 43.3
with an uncertainty of 5.5 arcsec.

Uncertainty radii are given at 90% containment.
All of the sources have count rates of ~1.3e-3 counts/s during this
observation.

It is not possible to determine whether these sources are fading
given the current statistics.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081025A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8411
SUBJECT: GRB 081025: Swift-XRT position
DATE:    08/10/26 11:08:44 GMT
FROM:    Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>

J. Mao, C. Guidorzi, R. Margutti (INAF-OAB) report on behalf of
the Swift-XRT team:

Swift began observing the field of the Swift-BATSS GRB 081025 (Copete et
al., GCN Circ. 8409) 74.5 ks after the trigger. In 2.9 ks of Photon
Counting mode data, we detect a single uncatalogued source within the
BAT error circle at a position of RA, Dec = 245.36626, 60.47428,
which is equivalent to

RA(J2000):   16 21 27.90
Dec(J2000): +60 28 27.4

with an uncertainty of 6.7 arcsec (radius, 90% containment). The source
lies 125 arcsec from the BAT centroid and has a count rate of
~3e-3 counts/s during this observation.

It is not possible to determine whether this source is fading given the
current statistics.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081025A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8412
SUBJECT: Konus-Wind observation of GRB 081025
DATE:    08/10/26 15:33:49 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin,
D. Frederiks, P. Oleynik, D. Svinkin, M. Ulanov
and T. Cline, on behalf of the Konus-Wind team report:

The long Swift-BATSS GRB 081025 (Copete et al., GCN 8409) triggered
Konus-Wind at T0=30186.316 s UT (08:23:06.316).

The burst light curve shows a multipeaked structure with a total 
duration of ~25 s.

As observed by Konus-Wind the burst
had a fluence of 5.37(-0.82, +0.96)x10^-6 erg/cm2,
and a 256-ms peak flux measured from T0-0.224 s
of 8.90(-2.62, +2.75)x10^-7 erg/cm2/s
(both in the 20 keV - 1 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+24.832 s) is well fitted (in the 20 keV-1 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.67(-0.33, +0.43) ,
and Ep = 222(-46, +81)  keV (chi2 = 55.5/60 dof).
Fitting by GRBM (Band) model yields only an upper limit on
the high energy photon index: beta < -2.07.

All the quoted errors are at the 90% confidence level.

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.ru/LEA/GRBs/GRB081025_T30186/


GRB_name: GRB081024B
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8413
SUBJECT: Swift UVOT observations of GRB081024B
DATE:    08/10/26 17:44:33 GMT
FROM:    Patricia Schady at MSSL/Swift  <msslba@yahoo.co.uk>

P. Schady (MSSL/UCL) and C. Guidorzi (INAF-OAB) report on behalf of the Swift UVOT team.

The Swift UltraViolet/Optical Telescope (UVOT) began observations of Fermi-LAT GRB 081024B (Omodei et al., GCN Circ. 8407) 70.3 ks after the trigger.

Source 1 and Source 2 in GCN Circ. 8410 (Guidorzi et al.) are outside the UVOT field of view, and no new source is detected at the position of Source 3 (GCN Circ 8410; Guidorzi et al.) down to the following 3 sigma upper limits:

Filter   Tstart(dys)  Exp(s)  3-sigma UL
v         1.215        885     > 20.33
b         0.824        864     > 21.26
u         0.814        2641    > 21.42
uvw1      0.894        1531    > 21.07
uvm2      0.883        2548    > 21.36
uvw2      1.163        1201    > 21.07
 
The values quoted above are on the UVOT Photometric System (Poole et al, 2008, MNRAS 383,627). They are not corrected for the expected Galactic extinction corresponding to a reddening of E(B-V)=0.07 mag in the direction of the burst (Schlegel et al. 1998).




      


GRB_name: GRB081025A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8414
SUBJECT: Swift UVOT observations of GRB081025
DATE:    08/10/26 17:50:10 GMT
FROM:    Patricia Schady at MSSL/Swift  <msslba@yahoo.co.uk>

P. Schady (MSSL/UCL) and J. Mao (INAF-OAB) report on behalf of the Swift UVOT team.

The Swift UltraViolet/Optical Telescope (UVOT) began ToO observations
of the Swift-BATSS GRB 081025 (Copete et al., GCN Circ. 8409), 20.7 hours
after the trigger. We do not detect any new source at the XRT position
reported in GCN Circ. 8411 (Mao et al.) in any of the individual or
co-added images down to the following 3-sigma upper limits:

Filter  Tstart(hrs)  Exp(s)  3-sigma UL
b        21.2        130     > 19.44
u        20.9        885     > 20.18
uvw1     20.7        1015    > 20.60
uvm2     22.2        886     > 20.63

The values quoted above are on the UVOT Photometric System
(Poole et al, 2008, MNRAS 383,627).  They are not corrected for the expected
Galactic extinction corresponding to a reddening of E(B-V)=0.02 mag
in the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB081025A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8415
SUBJECT: GRB 081025 BAT refined analysis
DATE:    08/10/26 19:12:08 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <jayc@milkyway.gsfc.nasa.gov>

J. R. Cummings (GSFC/UMBC), A. Copete (Harvard), J. Grindlay (Harvard),
S. D. Barthelmy (GSFC), N. Gehrels (GSFC), C. Guidorzi (INAF-OAB) 

Using the data set from T+9 to T+129 sec (T0 is here defined as the
beginning of the Swift slew manuever), we report further analysis of
BATSS GRB 081025 (Copete, et al., GCN Circ. 8409). 

Using the the previously reported position, the partial coding averaged 
over the event was 70%.  This is 2.1 arcmin from the XRT afterglow 
candidate (Mao et al. GCN Circ. 8411).

The mask-weighted lightcurve features a main peak starting at T+63 sec
lasting 12 sec, followed in succession by 3 peaks, a 1.4 sec long peak
at T+77 sec, a 4.2 sec long peak at T+83sec, and a 2.2 sec long peak at
T+88sec.  T90 (15-350 keV) is 23 +- 2 sec (estimated error including
systematics).

The time-averaged spectrum from T+63 to T+89 sec is best fit by a
simple power-law model.  The power law index of the time-averaged
spectrum is 1.12 +- 0.05.  The fluence in the 15-150 keV band is
(1.9 +- 0.2) x 10-06 erg/cm2.  The 1-sec peak photon flux measured from
T+68 sec in the 15-150 keV band is 1.3 +- 0.2 ph/cm2/sec.  All the
quoted errors are at the 90% confidence level.

The results of the analysis will be available (in a few days) at
http://gcn.gsfc.nasa.gov/notices_s/BATS0021/BA/


GRB_name: GRB081024B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8416
SUBJECT: GRB 081024B: Swift-XRT further observations
DATE:    08/10/26 23:17:31 GMT
FROM:    Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>

C. Guidorzi and R. Margutti (INAF-OAB) report on behalf of the
Swift-XRT team:

Swift re-observed the field of the Fermi-LAT GRB 081024B (Omodei et
al., GCN Circ. 8407) 127 ks after the burst. From 13.5 ks of Photon
Counting mode data, we found that sources 1 and 3 mentioned in our
previous report (Guidorzi et al. GCN Circ. 8410) are still detected
with a count rate compatible with being constant between the two
observations. Although source 2 is no longer detected, we estimate
that the fading is not statistically significant yet.
Further data will allow us to determine the possible fading.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081024B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8417
SUBJECT: GRB081024B: P200 Observations
DATE:    08/10/27 05:23:08 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko@srl.caltech.edu>

S. B. Cenko (UC Berkeley) and M. M. Kasliwal (Caltech) report on behalf of
a larger collaboration:

We have imaged the error circle of the short duration GRB081024B (Omodei,
GCN 8407; Connaughton and Briggs, GCN 8408) with the Large Format Camera
mounted on the Palomar 200 inch Hale telescope.  Images were taken in
the Sloan r' and i' filters at a mean epoch of approximately Oct 26.1 (~
30 hours after the burst).

We detect several sources inside or near the potential X-ray afterglow
(XRT Source 2; Guidorzi, Margutti, and Mao, GCN 8410; Guidorzi and
Margutti, GCN 8416).  Calibrating with respect to several nearby objects
in the USNO-B1 catalog, we note the following positions and magnitudes for
the four nearest sources:

O1 -  RA: 21:31:36.95   Dec: +21:16:35.4 (J2000)
      R = 20.6 mag

O2 -  RA: 21:31:37.63   Dec: +21:16:33.0 (J2000)
      R = 22.6 mag

O3 -  RA: 21:31:37.42   Dec: +21:16:36.4 (J2000)
      R = 23.4 mag

O4 -  RA: 21:31:37.32   Dec: +21:16:25.1 (J2000)
      R = 22.6 mag

We estimate the astrometric precision for each source is 0.5" in each
coordinate.  The photometric precision for the above reported magnitudes
is likely large (~ 0.3 mag) due to both zeropoint uncertainty and
bandpass differences.  The limiting magnitude of our co-added image is
approximately R > 23.5 mag.

We note that source O1 appears to be present in the DSS plates of this
field.  Additionally, source 02 is clearly extended.  None of the objects
show evidence for variability over the (limited) duration of our
observations.

An image of the field is posted at:

   http://www.srl.caltech.edu/~cenko/public/grb081024b.jpg

Further observations to search for variability are encouraged.


GRB_name: GRB081025A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8418
SUBJECT: GRB081025: RTT150 optical observations
DATE:    08/10/27 09:09:48 GMT
FROM:    Rodion Burenin at IKI, Moscow  <rodion@hea.iki.rssi.ru>

I. Khamitov (TUG), N. Aleksandrovich,
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),
I. Bikmaev, N. Sakhibullin (KSU/AST),
Z. Eker (TUG), U. Kiziloglu (METU),  E. Gogus (Sabanci Uni.)

report:

We observed the field of the Swift-BATSS GRB 081025 (Copete et al., GCN8409)
with Russian-Turkish 1.5-m  telescope (RTT150, Bakirlitepe, TUBITAK National
Observatory, Turkey), starting at 25 Oct, 19:51 UT, i.e. approximately 11.5 hours
after the burst, using Andor CCD.

We made 3x300s exposures in sdss-g filter, at high zenith distance (~70 degree)
and with bad seeing ~ 3". We do not detect any new source inside the XRT error circle
(Mao et al., GCN8411) as compared to DSS plates. Using photometric solution from
previous nights we estimated the limiting magnitude of combined image as m_g ~ 22. 


GRB_name: GRB081024A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8419
SUBJECT: GRB 081024: No radio detection with the VLA
DATE:    08/10/27 14:56:12 GMT
FROM:    Poonam Chandra at U Virginia/NRAO  <pc8s@virginia.edu>

Poonam Chandra (RMC) and Dale A. Frail (NRAO) report on
behalf of the Caltech-NRAO-Carnegie GRB Collaboration:

"We used the Very Large Array to observe the field of view toward
GRB 081024 (GCN 8398) at a frequency of 8.46 GHz at 2008 Oct. 25.27 UT. 
The GRB radio afterglow is undetected and the peak radio flux at the 
Swift XRT afterglow position (GCN 8403) is -36  52 uJy.

The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."


GRB_name: GRB081025A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8420
SUBJECT: GRB 081025: TLS upper limits
DATE:    08/10/28 00:28:59 GMT
FROM:    Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>

D. A. Kann, S. Schulze, C. Hoegner, S. Klose (TLS Tautenburg) and J. 
Greiner (MPE Garching) report:

We observed the BAT Slew GRB 081025 (A. Copete et al., GCN 8409) with the 
TLS Tautenburg 1.34m Schmidt telescope. Observations were initialized in 
RRM mode (S. Klose et al., GCN 3609) as the BAT_SLEW_POSITION had been 
received at dusk. After obtaining 2 x 120 sec Ic-band images, we realized 
the large time delay and switched to deeper imaging. We further obtained 2 
x 600 sec Ic-band images and one 600 sec Rc-band image.

At the position of the X-ray afterglow candidate (J. Mao et al., GCN 
8411), we do not detect any source. We find the following upper limits in 
comparison with the USNOB1.0 star at (catalog position, J2000) R.A. = 
16:21:28.125, Dec. = +60:28:42.35, which has R2 = 18.61, I = 17.84:

dt exp  Filter upper limit (2 sigma)

0.38672 2x120+2x600 Ic 21.5

0.40047 1x600  Rc 22.5

These limits are in agreement with the g-band limit of Khamitov et al. 
(GCN 8418).

We point out the existence of the galaxy cluster NSC 2162144+602602 at 
z=0.3903 (accoriding to SIMBAD) to the southeast of the afterglow 
position. The nearest galaxy (about 100" distant) seems to be a massive 
elliptical, possible a cD galaxy.

No further observations are planned.

This message may be cited.


GRB_name: GRB081028A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8421
SUBJECT: GRB 081028: Swift detection of a burst
DATE:    08/10/28 00:44:50 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

C. Guidorzi (INAF-OAB), W. H. Baumgartner (GSFC/UMBC),
A. P. Beardmore (U Leicester), J. R. Cummings (NASA/UMBC),
N. Gehrels (NASA/GSFC), S. T. Holland (CRESST/USRA/GSFC),
E. A. Hoversten (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL),
T. Sakamoto (NASA/UMBC), M. Stamatikos (NASA/ORAU) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:

At 00:25:00 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081028 (trigger=332851).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 121.890, +2.311 which is 
   RA(J2000) = 08h 07m 34s
   Dec(J2000) = +02d 18' 40"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  Although this is a BAT image trigger,
the BAT light curve showed at least two slowly rising and falling 
peak structure with a duration of about 250 sec.  The peak count rate
of the first peak was ~600 counts/sec (15-350 keV), at ~70 sec after the 
trigger.  The second peak was comparable in size peaking at ~210 sec. 

The XRT began observing the field at 00:28:11.5 UT, 190.7 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 121.8953, +2.3086 which is equivalent to:
   RA(J2000)  = 08h 07m 34.87s
   Dec(J2000) = +02d 18' 30.9"
with an uncertainty of 4.8 arcseconds (radius, 90% containment). This
location is 20 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

The initial flux in the 2.5 s image was 5.50e-09 erg cm^-2 s^-1 (0.2-10
keV). 


UVOT took a finding chart exposure of nominal 150 seconds with the White
(160-650 nm) filter starting 200 seconds after the BAT trigger. No afterglow
candidate has been found in the initial data products. Image catalog data are
not available at this time. The 8'x8' region for the list of sources generated
on-board covers 100% of the XRT error circle. The list of sources is typically
complete to about 18 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.03. 




Burst Advocate for this burst is C. Guidorzi (cristiano.guidorzi AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081024B
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8422
SUBJECT: Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
DATE:    08/10/28 01:22:45 GMT
FROM:    Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>

We observed the LAT error circle of the Fermi-LAT (Omodei, GCN 8407) and 
Fermi-GBM (Connaughton and Briggs, GCN 8408) detected short/hard GRB 
081024B with the TLS Tautenburg 1.34m Schmidt telescope in full frame mode 
(field of view 42' x 42'), covering the complete error circle to about 2 
sigma confidence level. We obtained 24 x 300 sec images in the Rc band 
under good observing conditions, at mid-time 0.88644 days after the GRB.

We report the following analysis of the three XRT sources (Guidorzi et 
al., GCN 8410), of which source 1 and 3 seem to remain constant (Guidorzi 
& Margutti, GCN 8416), whereas source 2 may be fading and thus represent 
the X-ray afterglow of GRB 081024B:

Source 1: We find a relatively bright stellar object which is clearly 
visible in the DSS.

Source 3: We find a moderately faint stellar object which is under the DSS 
limit.

Source 2: We detect all four objects reported by Cenko & Kasliwal (GCN 
8417). Source O3 is close to the detection limit, implying that it is ~ Rc 
> 23.5, similar to that of the P200 image.

We use several nearby, isolated USNOB1.0 stars to determine the image zero 
point. We find that the zero point error is 0.04 magnitudes from four 
stars, better than the pessimistic estimation (0.3 magnitudes) of Cenko & 
Kasliwal (which also includes bandpass differences). Photometry was done 
using a 7 pixel aperature (matched to the typical seeing) on sources O1 
and O4 (which are reasonably isolated). For sources O2 (close to a bright 
star) and O3 (close to O2), we used a 3 pixel aperature and used two 
bright, isolated stars to compute the aperature correction (a factor of 
2).

We derive the following magnitudes for the four sources (in brackets, we 
give the magnitudes of Cenko & Kasliwal):

O1 (bright, stellar): Rc = 20.55 +/- 0.04 (20.6)

O2 (extended in P200): Rc = 22.25 +/- 0.10 (22.6)

O3 (faint):  Rc = 23.48 +/- 0.34 (23.4)

O4 (faint, stellar): Rc = 22.53 +/- 0.16 (22.6)

All sources except O2 agree well with the P200 magnitudes obtained 0.36 
days later, to within +/- 0.08 magnitudes despite the multiple differences 
(comparison stars, bandpass, etc.). Only source O2 is brighter, by ~ 0.35 
magnitudes. While the source is close to a bright (~ magnitude of O1) 
star, which may contaminate the photometry even in the reduced aperature, 
O2 is clearly brighter in our image than O4, whereas they have identical 
magnitudes (as reported by Cenko & Kasliwal) in the P200 images. Since 
Cenko & Kasliwal report this source to be extended, this may indicate that 
we are seeing the optical afterglow as well as the underlying host galaxy 
of GRB 081024B. Still, caution is advised.

This GRB is of special interest. It is the first Fermi-detected short/hard 
GRB reported so far, and possibly the first one with a detection at >> 1 
GeV (the very bright GRB 930131, the "Superbowl Burst", was only detected 
to ~ 1 GeV by CGRO EGRET, Sommer et al. 1994, ApJL, 422, L63), and, 
similar to GRB 930131 and also the AGILE-Grid-detected long GRB 080514B 
(Guiliani et al. 2008, A&A, in press), emission is seen for several 
seconds longer than at lower energies. Therefore, additional deep 
follow-up and spectroscopy of extended source O2 is highly encouraged. 
Further observations at TLS are planned (to perform image subtraction) in 
case we ever see the stars again.

This message may be cited.


GRB_name: GRB081024B
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8423
SUBJECT: Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
DATE:    08/10/28 01:44:03 GMT
FROM:    Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>

D. A. Kann, S. Schulze and C. Hoegner (TLS Tautenburg) report:

We observed the LAT error circle of the Fermi-LAT (Omodei, GCN 8407) and 
Fermi-GBM (Connaughton and Briggs, GCN 8408) detected short/hard GRB 
081024B with the TLS Tautenburg 1.34m Schmidt telescope in full frame mode 
(field of view 42' x 42'), covering the complete error circle to about 2 
sigma confidence level. We obtained 24 x 300 sec images in the Rc band 
under good observing conditions, at mid-time 0.88644 days after the GRB.

We report the following analysis of the three XRT sources (Guidorzi et 
al., GCN 8410), of which source 1 and 3 seem to remain constant (Guidorzi 
& Margutti, GCN 8416), whereas source 2 may be fading and thus represent 
the X-ray afterglow of GRB 081024B:

Source 1: We find a relatively bright stellar object which is clearly 
visible in the DSS.

Source 3: We find a moderately faint stellar object which is under the DSS 
limit.

Source 2: We detect all four objects reported by Cenko & Kasliwal (GCN 
8417). Source O3 is close to the detection limit, implying that it is ~ Rc 
> 23.5, similar to that of the P200 image.

We use several nearby, isolated USNOB1.0 stars to determine the image zero 
point. We find that the zero point error is 0.04 magnitudes from four 
stars, better than the pessimistic estimation (0.3 magnitudes) of Cenko & 
Kasliwal (which also includes bandpass differences). Photometry was done 
using a 7 pixel aperature (matched to the typical seeing) on sources O1 
and O4 (which are reasonably isolated). For sources O2 (close to a bright 
star) and O3 (close to O2), we used a 3 pixel aperature and used two 
bright, isolated stars to compute the aperature correction (a factor of 
2).

We derive the following magnitudes for the four sources (in brackets, we 
give the magnitudes of Cenko & Kasliwal):

O1 (bright, stellar): Rc = 20.55 +/- 0.04 (20.6)

O2 (extended in P200): Rc = 22.25 +/- 0.10 (22.6)

O3 (faint):  Rc = 23.48 +/- 0.34 (23.4)

O4 (faint, stellar): Rc = 22.53 +/- 0.16 (22.6)

All sources except O2 agree well with the P200 magnitudes obtained 0.36 
days later, to within +/- 0.08 magnitudes despite the multiple differences 
(comparison stars, bandpass, etc.). Only source O2 is brighter, by ~ 0.35 
magnitudes. While the source is close to a bright (~ magnitude of O1) 
star, which may contaminate the photometry even in the reduced aperature, 
O2 is clearly brighter in our image than O4, whereas they have identical 
magnitudes (as reported by Cenko & Kasliwal) in the P200 images. Since 
Cenko & Kasliwal report this source to be extended, this may indicate that 
we are seeing the optical afterglow as well as the underlying host galaxy 
of GRB 081024B. Still, caution is advised.

This GRB is of special interest. It is the first Fermi-detected short/hard 
GRB reported so far, and possibly the first one with a detection at >> 1 
GeV (the very bright GRB 930131, the "Superbowl Burst", was only detected 
to ~ 1 GeV by CGRO EGRET, Sommer et al. 1994, ApJL, 422, L63), and, 
similar to GRB 930131 and also the AGILE-Grid-detected long GRB 080514B 
(Guiliani et al. 2008, A&A, in press), emission is seen for several 
seconds longer than at lower energies. Therefore, additional deep 
follow-up and spectroscopy of extended source O2 is highly encouraged. 
Further observations at TLS are planned (to perform image subtraction) in 
case we ever see the stars again.

We are indebted to Antonio de Ugarte Postigo for pointing out the 
suspicious lack of authors in the first version.

This message may be cited.


GRB_name: GRB081028A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8424
SUBJECT: GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
DATE:    08/10/28 07:44:21 GMT
FROM:    Christian Clemens at MPE  <cclemens@mpe.mpg.de>

C. Clemens, S. Loew and J. Greiner (all MPE Garching) report on behalf of the 
GROND team:

We observed the field of GRB 081028 (Swift trigger 332851; Guidorzi et al., 
GCN #8421) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, 
PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla Observatory 
(Chile).

Observations started at 06:19 UT on October 28th, 2008, 5.8 hr after the GRB 
trigger, and are continuing. They were performed at an average seeing of 1.4" 
and at an average airmass of 2.4.

We found a single point source within the 4.8'' Swift-XRT error circle 
reported by Guidorzi et al. (GCN #8421) at

RA (J2000) = 08h 07m 34.73s
DEC (J2000) = +02d 18' 29.1''

with an uncertainty of 0.5".

Based on the first 4.4 min of total exposures in g'r'i'z' and 4.0 min in JHK, 
we estimate preliminary magnitudes (all in AB system) of

g' ~ 19.9 mag,
r' ~ 19.3 mag,
i' ~ 19.2 mag,
z' ~ 19.1 mag,
J ~ 19.0 mag,
H ~ 18.7 mag and
K ~ 19.0 mag

with typical errors of +/- 0.1 in g'r'i'z' and +/- 0.15 in JHK. Given 
magnitudes are calibrated against SDSS as well as 2MASS field stars.

The object is seen in g' band, implying a redshift smaller than 3.5 and no 
statement about variability can be made at this point.

Please note, that no correction for the Galactic foreground extinction 
corresponding to a reddening of E_(B-V)= 0.03 mag in the direction of the 
burst (Schlegel et al. 1998) has been applied.


GRB_name: GRB081028A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8425
SUBJECT: GRB 081028: optical observations at the NOT
DATE:    08/10/28 07:47:36 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@astro.ku.dk>

G. Olofsson (Stockholm), Johan P. U. Fynbo (DARK/NBI), and P. Jakobsson 
(Univ. Iceland) report:

We observed the field of GRB 081028 (Guidorzi et al., GCN 8421) with the 
NOT equipped with PolCor. Observations started on 2008 Oct 28, around 6 
UT (more accurate information will follow).

At a position consistent with the X-ray error circle, we detect a bright 
object at the following coordinates:

RA(J2000) = 08:07:34.721
Dec(J2000) = +02:18:29.03

Given the small field of view, only four stars are available for 
astrometry. Assuming R = 15.7 for the USNO star at RA=08:07:33.70, Dec = 
+02:18:39.9, we compute R ~ 19.2 for the afterglow.

Our astrometry and photometry are consistent with those reported by 
Clemens et al. (GCN 8424). The object is not visible in the DSS nor in 
the SDSS, hence we are confident it is the afterglow of GRB 081028.

A finding chart is available on request.


GRB_name: GRB081028A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8426
SUBJECT: GRB 081028: TAROT Calern observatory optical observations
DATE:    08/10/28 09:19:04 GMT
FROM:    Bruce Gendre at LAM-OAMP  <bruce.gendre@oamp.fr>

Gendre, B (LAM-OAMP), Klotz, A. (CESR-OMP), Boer M. (OHP), Atteia J.L. 
(LATT-OMP) report:

We imaged the field of GRB 081028 detected by SWIFT
(trigger 332851) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 566.4s after the GRB trigger
(423.2s after the notice). The elevation of the field increased
from 16 degrees above horizon and weather conditions
were very poor.

The first useful image started 4054.0 s after the notice. We co-added all 
exposure between 4054 and 6499 seconds. At the position reported by Clemens 
et al. (GCN 8424) and Olofsson et al. (GCN 8425), we do not detect any 
transient source, with a limit of R ~ 17.4. We do not detect any other 
source not present in the DSS.

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.

This message may be cited.


GRB_name: GRB081028A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8427
SUBJECT: GRB 081028: Enhanced Swift-XRT position
DATE:    08/10/28 09:33:20 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 5305 s of XRT Photon Counting mode data and 8 UVOT
images for GRB 081028, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 121.8948, +2.3083 which is equivalent
to:

RA (J2000): 08h 07m 34.76s
Dec (J2000): +02d 18' 29.8"

with an uncertainty of 1.5 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081028A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8428
SUBJECT: GRB 081028, Swift-BAT refined analysis
DATE:    08/10/28 11:54:31 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), C. Guidorzi (INAF-OAB),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL),
T. Sakamoto (GSFC/UMBC), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 081028 (trigger #332851)
(Guidorzi, et al., GCN Circ. 8421).  The BAT ground-calculated position is
RA, Dec = 121.893, 2.305 deg, which is 
   RA(J2000)  =  08h 07m 34.4s 
   Dec(J2000) = +02d 18' 16.8" 
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 85%.
 
The mask-weighted light curve shows two main peaks and a tail.
The first peak starts at ~T+20 sec, peaks at ~T+80 sec, and falls
to a minumum betwen the two peaks at ~T+140 sec.  The second peak
peaks at ~T+220 sec.  There is a tail out to approximately T+400 sec.
T90 (15-350 keV) is 260 +- 40 sec (estimated error including systematics).
 
The time-averaged spectrum from T+29.3 to T+441.5 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.25 +- 0.38, 
and Epeak of 58 +- 23 keV (chi squared 57.6 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 3.7 +- 0.2 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+211.74 sec in the 15-150 keV band is
0.5 +- 0.1 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.84 +- 0.09 (chi squared 63.9 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/332851/BA/


GRB_name: GRB081028A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8429
SUBJECT: GRB 081028: Swift-XRT refined analysis
DATE:    08/10/28 12:05:18 GMT
FROM:    Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>

C. Guidorzi, R. Margutti, J. Mao (INAF-OAB) on behalf of the Swift-XRT
team report:

We have analysed the first 6 orbits of Swift-XRT data obtained for GRB
081028 (Guidorzi et al., GCN Circ. 8421), covering 650 s of Windowed
Timing and 12.5 ks of Photon Counting (PC) mode data, between 197 s and
29 ks after the trigger. The UVOT-enhanced XRT position was given by
Evans et al. in GCN Circ. 8427.

The light-curve shows a very complex evolution. In the first orbit data,
covered entirely in WT mode, from 200 to 300 s it can be fit with a
power law decay with an index of ~0.5. This temporally coincides with
the decay of the second peak observed by BAT, which peaked at 220 s
(Barthelmy et al. GCN Circ. 8428). Afterwards, there
is flaring activity up to 400 s. From 400 to 700 s the afterglow
undergoes a steep decay with a power-law index of 3.4, followed by
a large flare with a peak rate of ~30 counts/s and lasting longer
than 150 s. First orbit data stopped during the peak of this flare.
 From 4.1 to 8 ks the curve exhibits a steep decay with
a power-law index of 3.8 +- 1.2 and the count rate drops to a value
of ~5e-2 counts/s, after which it experiences a long rebrightening
(at least up to 29 ks) with flaring activity, reaching a peak count
rate of ~0.3 counts/s.

During the first orbit, the WT data spectrum undergoes a significant
hard-to-soft evolution, with Gamma changing from 1 to 3.
A WT spectrum extracted during the steep decay from 400 to 700 s
can be modelled with an absorbed power-law, with Gamma = 2.51 +- 0.07
and NH = (8.0 +- 1.1)e20 cm^-2, in excess of the Galactic column
in this direction of 4.0e20 cm^-2. The observed (unabsorbed) flux
over this time interval is 7.8e-10 (1.1e-9) erg cm^-2 s^-1.
A PC spectrum extracted from 5.0 to 23.2 ks can be modelled with an
absorbed power-law, with Gamma = 2.25 +- 0.16 and
NH = (9.3 +- 3.4)e20 cm^-2. The observed (unabsorbed) flux
over this time interval is 7.3e-12 (1.0e-11) erg cm^-2 s^-1.

Presently, given the ongoing flaring behaviour, we cannot provide a
reliable projection of the count rate over the next hours.

The results of the xrt automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00332851.

This is an official product of the Swift-XRT team.


GRB_name: GRB081028A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8430
SUBJECT: Swift UVOT observations of GRB081028
DATE:    08/10/28 12:41:00 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps@mssl.ucl.ac.uk>

P. Schady (MSSL-UCL) and C. Guidorzi (INAF-OAB) report on behalf of  
the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 081028  
201s after the BAT detection (Guidorziet al., GCN Circ. 8421). No  
source is detected in any of the individual or coadded exposures in  
any of the UVOT filters at the XRT position (GCN Circ. 8427), or at  
the position of the reported optical counterpart (GCN Circ. 8424, GCN  
Circ. 8425).  The 3 sigma upper limits at the position of the optical  
counterpart for the first white finding chart (fc) and in consequent  
co-added observations are reported below (where T_start and T_stop  
represent the elapsed time since the BAT trigger in seconds).

Filter  T_start(s) T_stop(s)  Exp(s)   3 sigma Upper Limit
white     201           350           146         > 20.95
white     481           846            58           > 20.05
v             357          722            58           > 18.50
b             456          821            58           > 19.33
u             432          796            58           > 18.98
uvw1      407         771             58           >19.01
uvm2      382         746             58           >18.70
uvw2      506          868            55           >19.01

The above magnitudes are not corrected for the Galactic extinction  
corresponding to a reddening of E(B-V) = 0.03 mag (Schlegel et al.,  
1998, ApJS, 500, 525).  The photometry is on the UVOT photometric  
system described in Poole et al. (2008, MNRAS, 383,627).


GRB_name: GRB081028A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8431
SUBJECT: GRB081028: UVOT detection of a brightening afterglow
DATE:    08/10/28 15:40:08 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps@mssl.ucl.ac.uk>

P. Schady (MSSL-UCL) and C. Guidorzi (INAF-OAB) report on behalf of  
the Swift/UVOT team:

Further to the UVOT observations of GRB 081028 reported in GCN Circ.  
8430 (Schady et al.), we report an afterglow detection at the position  
of the optical counterpart (GCN Circ. 8424, GCN Circ. 8425) in later  
UVOT observations, from 10,000s after the BAT trigger. This is  
suggestive of a re-brightening of the afterglow consistent with the  
time of the brightening observed in the XRT light curve (Guidorzi et  
al., GCN Circ. 8429). The afterglow is detected in the v, b and u-band  
filters. The detection of the afterglow in the u-filter suggests a  
photometric upper limit on the redshift of z < ~2.3.

The magnitudes of the afterglow and 3-sigma upper limits are reported  
below:

Filter Tstart(s)   Tstop(s)    Exp(s)    Magnitude/3-sig UL
v          4050         5684        393.2        > 20.13
v          10740       28995     1770.3      20.23 +/- 0.19

b          4870         6504        393.3        > 20.79
b          17436       35567     1433.5     20.19 +/- 0.14

u          4665         6299        393.2       > 20.53
u          16524       34778     2539.8     21.21+/- 0.26

uvw1   4460         6094        393.2       > 20.61
uvw1   15618      33865      2656.7     > 21.89

uvm2   4255        5889        393.2        > 20.51
uvm2   21399      29784     2428.5      > 21.66

uvw2   5281         5480       196.6        >  20.23
uvw2   29001      28082     1771.2      >  20.61


The above magnitudes are not corrected for the Galactic extinction  
corresponding to a reddening of E(B-V) = 0.03 mag (Schlegel et al.,  
1998, ApJS, 500, 525). The photometry is on the UVOT photometric   
system described in Poole et al. (2008, MNRAS, 383,627).


GRB_name: GRB081021A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8432
SUBJECT: GRB 081021: Fermi GBM detection
DATE:    08/10/28 16:27:20 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE) and E. Bissaldi (MPE)
report on behalf of the Fermi GBM Team:

"At 09:33:28 UT on 21 October 2008, the Fermi GBM triggered
and located GRB 081021 (trigger 246274409 / 081021398).
The on-ground calculated location, using the GBM trigger
data, is RA = 197.9, DEC = -25.1 (J2000 degrees,
equivalent to 13h 12m, +25d 06'), with an uncertainty
of 2.2 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
The angle from the Fermi LAT boresight is 125 degrees.

This GRB has one isolated peak, which is about 25 sec long. 
The time-averaged spectrum (10-1000 keV) from T0-3.8 s to T0+15.6 s 
is best fit by a Band function with Epeak = 117 +/- 11 keV, 
alpha = 0.11 +/- 0.25, and beta = -2.8 +/- 0.4.

The fluence (10-1000 keV) in this time interval from the
Band model is (5.3 +/- 0.6)E-06 erg/cm^2. 
The 1 sec peak photon flux measured starting from T0+2.3 s 
in the 10-1000 keV band is 4.2 +/- 0.9 ph/s/cm^2.

The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081028B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8433
SUBJECT: GRB 081028B: Fermi GBM detection
DATE:    08/10/28 21:57:03 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs@mpe.mpg.de>

E. Bissaldi (MPE) and A. von Kienlin (MPE)
report on behalf of the Fermi GBM Team: 


"At 12:55:08 UT on 28 October 2008, the Fermi GBM triggered
and located GRB 081028B (trigger 246891309 / 081028538).
The on-ground calculated location, using the GBM trigger data, 
is RA = 19.8, Dec = -23.5 (J2000 degrees,
equivalent to 1h 19m, -23d 30'), with an uncertainty
of 6.2 degrees (radius, 1-sigma containment, statistical only; 
there is additionally a systematic error which is currently 
estimated to be 2 to 3 degrees).
The angle from the Fermi LAT boresight is 107 degrees.

This long GRB is single peaked, with an estimated T90 (50-300 keV)
of about 20 s. The time-averaged spectrum (10-1000 keV) from T0-5.1 s to
T0+7.1 s is well fit by a power law function with an exponential 
high-energy cutoff.  The cutoff energy, parameterized as Epeak, 
is 70 +/- 4 keV with a power law index of -0.55 +/- 0.16. 

The fluence (10-1000 keV) in this time interval is 
(2.0 +/- 0.3)E-06 erg/cm^2. The 1 sec peak photon flux measured starting
from T0+1.5 s in the 10-1000 keV band is 6.9 +/- 0.5 ph/s/cm^2.


The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081028A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8434
SUBJECT: GRB 081028:  Magellan redshift
DATE:    08/10/28 21:57:17 GMT
FROM:    Edo Berger at Harvard  <eberger@cfa.harvard.edu>

E. Berger, R. Foley (Harvard), R. Simcoe (MIT), and J. Irwin (U. Michigan)
report:

"We observed the optical afterglow (GCNs 8424, 8425, 8430) of GRB 081028
(GCN 8421) with the Magellan Echellette Spectrograph (MagE) on the
Magellan/Clay 6.5-m telescope starting on 2008 Oct. 28.326 UT for a total
integration time of 1800 sec.  We find a wide range of absorption features
(including Ly-alpha, SII, NV, SiIV, CIV, FeII, etc.) at a redshift of
z=3.038, which we interpret as the redshift of the GRB.  In addition, we
find several intervening CIV and MgII absorbers."


GRB_name: GRB081029A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8435
SUBJECT: GRB 081029: Swift detection of a burst
DATE:    08/10/29 01:52:55 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

T. Sakamoto (NASA/UMBC), W. H. Baumgartner (GSFC/UMBC),
D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), C. Gronwall (PSU),
C. Guidorzi (INAF-OAB), S. T. Holland (CRESST/USRA/GSFC),
H. A. Krimm (CRESST/GSFC/USRA), J. Mao (INAF-OAB),
D. M. Palmer (LANL), M. Stamatikos (NASA/ORAU) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:

At 01:43:56 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081029 (trigger=332931).  Swift could not immediately slew
to the burst due to an Earth limb constraint. 
The BAT on-board calculated location is 
RA, Dec 346.704, -68.160 which is 
   RA(J2000) = 23h 06m 49s
   Dec(J2000) = -68d 09' 34"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  As is usual for an image trigger, 
the BAT light curve shows nothing remarkable. 

Due to an observing constraint, Swift will not slew until 
T0+41.3 minutes. There will be no XRT or UVOT data until
that time. 

Burst Advocate for this burst is T. Sakamoto (Taka.Sakamoto AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081029A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8436
SUBJECT: GRB 081029: ROTSE-III Detection of Optical Counterpart 
DATE:    08/10/29 01:57:59 GMT
FROM:    Eli Rykoff at UCSB  <erykoff@physics.ucsb.edu>

E.S. Rykoff (UCSB), report on behalf of the ROTSE collaboration:

ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, 
responded to GRB 081029 (Swift trigger 332931, GCN 8435, Sakamoto et 
al.). The first image was at 01:45:22.8 UT, 86.0 s after the burst (8.8 
s after the GCN notice time). The unfiltered images are calibrated 
relative to USNO A2.0. We detect a 16.5 magnitude, fading source with 
coordinates:

      23:07:05.36      -68:09:19.74    (J2000), with positional 
uncertainty of 1" or better

start UT     mag     mlim(of image)
----------------------------------
01:45:22.8     16.5     17.8


This source is not visible in DSS (second epoch), 2MASS or the MPChecker 
database.

A jpeg image is available at 
http://www.rotse.net/images/gsb332931_3c011-020_key.jpg Note that the 
object marked 36 is the candidate in question.

Continuing observations are in progress.


GRB_name: GRB081029A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8437
SUBJECT: GRB 081029: GROND Detection of the Optical/NIR Afterglow
DATE:    08/10/29 02:49:45 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

C. Clemens, S. Loew and J. Greiner (all MPE Garching) report on behalf of the 
GROND team:

We observed the field of GRB 081029 (Swift trigger 332931; Sakamoto et al., 
GCN #8435) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, 
PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla Observatory 
(Chile).

Observations started at 01:52 UT on October 29th, 2008, 8.2 min after the 
GRB trigger, and are continuing. They were performed at an average seeing 
of 1.0" and at an average airmass of 1.3.

We found a bright point source at the position reported by Rykoff et al. 
(GCN #8436), at magnitude r'=17.8 during the first 4 min integration,
calibrated with the GROND zeropoint.

The object is seen in g' band, implying a redshift smaller than 3.5.


GRB_name: GRB081029A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8438
SUBJECT: GRB 081029: UVES/VLT Absorption Redshift 
DATE:    08/10/29 06:08:18 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

V. D'Elia, (INAF-OAR), S. Covino, P. D'Avanzo (INAF-OAB), report on 
behalf of
the MISTICI collaboration

Following the detection of GRB 081029 (Sakamoto et al. GCN 8435), we 
triggered observations with the UVES camera, mounted at ESO-VLT. The 
observations were performed using both dichroics. We took two  spectra 
starting around Oct 29 at 02:06 UT (about 23 minutes after the burst) 
and covering the range 300-1000 nm.

We detect several absorption features, both ground and fine structure, 
namely, the SiII 1253, SiII 1260, SiII* 1264, OI 1302, SiII 1304, SiII* 
1309, CII 1334 and CII* 1335. These features are interpreted as produced 
by the gas in the GRB host galaxy, at the redshift z=3.8479+/-0.0002

Further analysis is in progress.

We are very grateful for the excellent support of the VLT staff and in 
particular to Antonio De Ugarte Postigo.


GRB_name: GRB080411A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8439
SUBJECT: Radio observation of GRB 080411 with ATCA
DATE:    08/10/29 07:38:56 GMT
FROM:    Aquib Moin at CIRA/ATNF  <aquib.moin@postgrad.curtin.edu.au>

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the BAT refined position of the GRB 080411 (GCN 7591) at 4.8
and 8.456 GHz with the Australia Telescope Compact Array (ATCA) on June
01, 2008 between 03:43:05 UT and 09:43:35 UT.

We did not detect a radio source at the BAT position of the GRB 080411
(GCN 7591). The radio flux density at the GRB position is -0.101 +/-
0.324 mJy at 4.8 GHz and 0.188 +/- 0.374 mJy at 8.456 GHz (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See field image at:

http://astronomy.ivec.org/dokuwiki/doku.php/grb/grb_080411_field_image 


GRB_name: GRB080303A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8440
SUBJECT: Radio observation of GRB 080303 with ATCA
DATE:    08/10/29 08:03:29 GMT
FROM:    Aquib Moin at CIRA/ATNF  <aquib.moin@postgrad.curtin.edu.au>

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the BAT refined position of the GRB 080303 (GCN 7359) at 4.8
and 8.456 GHz with the Australia Telescope Compact Array (ATCA) on May
31, 2008 between 04:09:05 UT and 14:19:35 UT.

We did not detect a radio source at the BAT position of the GRB 080303
(GCN 7359). The radio flux density at the GRB position is -0.384 +/-
0.303 mJy at 4.8 GHz, and 0.078 +/- 0.250 mJy at 8.6 GHz (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See field image at:

http://astronomy.ivec.org/dokuwiki/doku.php/grb/grb_080303_field_image 


GRB_name: GRB081029A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8441
SUBJECT: GRB 081029: REM observations
DATE:    08/10/29 08:12:57 GMT
FROM:    Stefano Covino at Brera Astronomical Observatory  <stefano.covino@gmail.com>

S. Covino, P. D'Avanzo, L.A. Antonelli, D. Malesani, D. Fugazza, L.  
Calzoletti,  S. Campana, G.  Chincarini, M.L. Conciatore, S. Cutini,  
V. D'Elia,  F. D'Alessio, F.  Fiore, P. Goldoni, D. Guetta,  C.  
Guidorzi, G.L. Israel, E. Maiorano, N. Masetti, A. Melandri, E.  
Meurs, L. Nicastro, E. Palazzi, E. Pian, S. Piranomonte, L.  Stella,  
G.  Stratta, G. Tagliaferri, G. Tosti, V.Testa, S.D. Vergani, F.  
Vitali report on behalf of the REM team:

The robotic 60-cm REM telescope located at La Silla (Chile) observed  
automatically the field of the GRB 081029 (Sakamoto et al., GCN 8435)  
on Oct  29, starting about 2 min after the burst time. The afterglow  
reported by Rykoff et al. (GCN 8436) and Clemens et al. (GCN 8437) is  
clearly detected both in the optical and infrared bands at a  
magnitude level H~14.6 about 2.5 min after the burst.

[GCN OPS NOTE(29oct08): Per author's request, the second (duplicate)
author was replaced with "P. D'Avanzo".]


GRB_name: GRB081028A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8442
SUBJECT: GRB 081028: GROND Confirmation of the Optical/NIR Afterglow
DATE:    08/10/29 09:00:11 GMT
FROM:    Christian Clemens at MPE  <cclemens@mpe.mpg.de>

C. Clemens, T. Kruehler and J. Greiner (all MPE Garching) report on behalf of 
the GROND team:

We observed the field of GRB 081028 for a second time at 07:45 UT on October 
29th, 2008, 31.3 hr after the GRB trigger with 460 s of total exposures in 
g'r'i'z' and 480 s in JHK. Observations were performed at an average seeing 
of 1.3" and at an average airmass of 1.5.

We still detect the bright afterglow within the refined 1.5'' Swift-XRT error 
circle (Evans et al., GCN #8427) with the following preliminary magnitudes 
(all in AB system) of

g' ~ 21.26 mag,
r' ~ 20.49 mag,
i' ~ 20.24 mag,
z' ~ 19.99 mag and
J ~ 19.6 mag

with statistical errors of +/- 0.05 in g'r'i'z' and +/- 0.1 in J. Given 
magnitudes are calibrated against SDSS as well as 2MASS field stars.

These measurements demonstrate a strong fading of the source compared to our 
first epoch observations (Clemens et al., GCN #8424). We therefore confirm 
this to be the afterglow of GRB 081028.

No correction for the Galactic foreground extinction corresponding to a 
reddening of E_(B-V)= 0.03 mag in the direction of the burst (Schlegel et al. 
1998) has been applied.


GRB_name: GRB081029A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8443
SUBJECT: GRB 081029: Enhanced Swift-XRT position
DATE:    08/10/29 09:11:14 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2569 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 081029, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 346.7729, -68.1561 which is equivalent
to:

RA (J2000): 23h 07m 5.51s
Dec (J2000): -68d 09' 21.9"

with an uncertainty of 1.5 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081024B
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8444
SUBJECT: GRB 081024B: Suzaku WAM observation of the prompt emission
DATE:    08/10/29 09:50:05 GMT
FROM:    Yoshitaka Hanabata at Hiroshima U  <hanabata@hep01.hepl.hiroshima-u.ac.jp>

Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira (Hiroshima U.),
T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), S. Sugita, 
K. Yamaoka (Aoyama Gakuin U.),  M. Ohno, M. Kokubun, M. Suzuki, 
T. Takahashi (ISAS/JAXA), Y.E. Nakagawa, T. Tamagawa (RIKEN), 
M. Tashiro, Y. Terada, Y. Urata, A. Endo, K. Onda, 
N. Kodaka, K. Morigami, T. Sugasahara, W. Iwakiri (Saitama U.),
E. Sonoda, M. Yamauchi, H. Tanaka, R. Hara, N. Ohmori (Univ. of Miyazaki),
S. Hong (Nihon U.), on behalf of the Suzaku WAM team, report:

The short/hard GRB081024B (Fermi-LAT detected ; Omodei GCN8407,
Fermi-GBM triggered ; Connaughton and Briggs, GCN 8408) triggered the
Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range
of 50 keV - 5 MeV at 21:22:40.526 UT (=T0). 

The observed light curve shows double-peaked structure with a duration
(T90) of about 0.4 second. 
The fluence in 100 - 1000 keV was 2.7(+0.7, -1.0) X 10^-7 erg/cm^2. 
The peak flux within 0.5 second was 1.1(+0.3, -0.5) photons/cm^2/s in
the same energy range.

Preliminary result shows that even at least 2 MeV photons have been
detected, and the time-averaged spectrum from T0 to T0+0.5s is well
fitted by a single power-law with a photon index of 1.24(+0.25, -0.19)
(chi^2/d.o.f = 12.3/14). All the quoted errors are at statistical 90%
confidence level, in which the systematic uncertainties are not included. 

The light curves for this burst are availabel at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html


GRB_name: GRB081025A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8445
SUBJECT: GRB 081025: Suzaku WAM observation of the prompt emission
DATE:    08/10/29 09:53:27 GMT
FROM:    Yoshitaka Hanabata at Hiroshima U  <hanabata@hep01.hepl.hiroshima-u.ac.jp>

C. Kira, Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa(Hiroshima U.),
T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), S. Sugita,
K. Yamaoka (Aoyama Gakuin U.),  M. Ohno, M. Kokubun, M. Suzuki,
T. Takahashi (ISAS/JAXA), Y.E. Nakagawa, T. Tamagawa (RIKEN),
M. Tashiro, Y. Terada, Y. Urata, A. Endo, K. Onda,
N. Kodaka, K. Morigami, T. Sugasahara, W. Iwakiri (Saitama U.),
E. Sonoda, M. Yamauchi, H. Tanaka, R. Hara, N. Ohmori, K. Kono, H.Hayashi,
(Univ. of Miyazaki),S. Hong (Nihon U.), on behalf of the Suzaku WAM team, report:

The long GRB 081025 (Copete et al., GCN 8409)
triggered the Suzaku Wide-band  All-sky Monitor (WAM)
which covers an energy range of 50 keV - 5 MeV at 2008-10-25 08:23:07 UT (=T0).
The observed light curve shows a multi-peaked structure
starting at T0-0.5s, ending at T0+21.5s,
with a duration (T90) of about 22 seconds.
The fluence in 100 - 1000 keV was 3.8(-0.7, +0.5)*10^-06 erg/cm^2.
The 1-s peak flux measured from T0 was 1.5 +/- 0.2 photons/cm^2/s
in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-0.5s to
T0+21.5s is well fitted by a single power-law with a photon index
of 1.93 (-0.25, +0.29) (chi^2/d.o.f = 10/9).

All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.

The light curves for this burst are available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html


GRB_name: GRB081029A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8446
SUBJECT: GRB081029: Swift XRT refined analysis
DATE:    08/10/29 11:10:09 GMT
FROM:    Jirong Mao at INAF-OAB  <jirong.mao@brera.inaf.it>


J. Mao, R. Margutti, C. Guidorzi (INAF-OAB) and T. Sakamoto (NASA/ UMBC)
report on behalf of the Swift-XRT team:

We have analysed the first 3 orbits of Swift-XRT data obtained for
GRB 081029 (Sakamoto et al., GCN Circ. 8435).
From T+2.7 to T+16.7 ks after the burst, data were collected in Photon
Counting (PC) mode with a total net exposure of 7 ks.
The UVOT-enhanced position was given by Goad et al. in GCN Circ. 8443.

The light curve shows a decay that can be fit with a simple power law
with an index of 0.57 +- 0.05.

The PC spectrum accumulated between T+2.7 and T+16.7 ks can be fit with a
absorbed power-law model with a photon index of 1.9 +- 0.1 and an
absorbing equivalent hydrogen column density consistent with the
Galactic one in the GRB direction (2.7e20 cm^-2; Kalberla et al.  2005).
The observed (unabsorbed) 0.3-10 keV flux is 6.9(7.5)e-12 erg cm^-2  s^-1.

If the light-curve continues to decay with alpha ~ 0.57, the count  rate 24
hours after the burst is estimated to be 0.03 count s^-1, which
corresponds to an observed flux of 2.1e-12 erg cm^-2 s^-1.

This is an official product of the Swift-XRT team.

[GCN OPS NOTE(29oct08): Per author's request, the GRB name in the subject
was changed from 080229 to 081029.]


GRB_name: GRB081029A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8447
SUBJECT: GRB 081029: Swift-BAT refined analysis
DATE:    08/10/29 12:48:10 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 081029 (trigger #332931)
(Sakamoto, et al., GCN Circ. 8435).  The BAT ground-calculated position is
RA, Dec = 346.776, -68.179 deg, which is 
   RA(J2000)  =  23h 07m 06.3s 
   Dec(J2000) = -68d 10' 43.4" 
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 58%.
 
The mask-weighted light curve shows a single relatively smooth peak
starting at ~T-50 sec, peaking at ~T+60 sec, and ending at ~T+300 sec.
T90 (15-350 keV) is 270 +- 45 sec (estimated error including systematics).
 
The time-averaged spectrum from T-35.6 to T+268.6 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.43 +- 0.18.  The fluence in the 15-150 keV band is 2.1 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+52.37 sec in the 15-150 keV band
is 0.5 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/332931/BA/


GRB_name: GRB081029A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8448
SUBJECT: GRB 081029: Redshift Confirmation from Gemini-South
DATE:    08/10/29 14:43:19 GMT
FROM:    Antonino Cucchiara at PSU  <cucchiara@astro.psu.edu>

A. Cucchiara, D. B. Fox (Penn State), S. B. Cenko  (Berkeley) and E. Berger
(Harvard) report on behalf of a larger collaboration:

Starting at 07:04 UT on 2008 November 29 (T0+5h) we observed the optical
counterpart of GRB 081029 (Sakamoto et al., GCN 8435, Rykoff  et al.,
GCN 8436) using Gemini-South with the GMOS-South spectrograph (R~1600).
We acquired 2x900s spectra covering the wavelength range 4000A-8000A.

We detect a damped Lyman-alpha system (DLA) at redshift z=3.847.

We also detect several metal absorption features which we interpret as
SiIV(1393,1402), SiII1526 and 1260, SiII*1264, CI1560, CII1334, CII*1335,
CIV(1548,1550), FeII1608, NV(1238,1242) at the same redshift.

In combination with the strong metal absorption features, the detection of
a DLA at z=3.847 confirms that this is the redshift of GRB 081029 and its
host galaxy.

Our results are consistent with those of D'Elia et al. (GCN 8438).

We thank the Gemini staff, in particular Rodrigo Damele, for conducting
these observations.


GRB_name: GRB081029A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8449
SUBJECT: GRB 081029: PROMPT Detections
DATE:    08/10/29 15:35:18 GMT
FROM:    James Philip West at UNC/Chapel Hill  <jpwest@uncg.edu>

J. P. West, J. Haislip, T. Brennan, D. Reichart, M. Nysewander, A. LaCluyze,
K. Ivarsen, J. A. Crain, A. Foster, R. Holmes, M. Schubel, R. Rhine, J.
Styblova, A. Trotter, and E. Weaver report:

Skynet observed the localization of GRB 081029 (Sakamoto et al., GCN 8435)
with three of the 16" PROMPT telescopes at CTIO beginning 92 seconds after
the trigger (64 seconds after notification) in BVRI.

We detect the afterglow (Rykoff et al., GCN 8436) in individual exposures in
VRI.  At 147 seconds after the burst we measure V ~ 16.8 mag (calibrated to
9 NOMAD stars), at 174 seconds we measure R ~ 15.7 mag (calibrated to 10
USNO stars), and at 296 seconds we measure I ~ 15.8 mag (calibrated to 10
USNO stars).


GRB_name: GRB081029A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8450
SUBJECT: GRB 081029: UVOT Detection of the Optical Afterglow
DATE:    08/10/29 16:41:01 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <sholland@milkyway.gsfc.nasa.gov>

S. T. Holland (CRESST/USRA/GSFC) & T. Sakamoto (NASA/UMBC) report on
behalf of the Swift/UVOT team:

        The Swift/UVOT observed the field of GRB 081029 starting 2708 s
after the BAT trigger (Sakamoto et al., 2008, GCNC 8435).  The late
start to the follow-up observations is due to an Earth limb constraint
at the time of the BAT trigger.  We detect the optical afterglow
(Rykoff et al., GCNC 8436) in the v, b, and white filters.  This is
consistent with a redshift of z = 3.8479 (D'Elia, et al., 2008, GCNC
8438).  The refined UVOT source position is

   RA (J2000) =  23:07:05.35 = 346.77229 (deg)
  Dec (J2000) = -68:09:19.8  = -68.15549 (deg)

with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence,
statistical + systematic).

      Magnitudes and 3-sigma upper limits are reported below.  TSTART
and TSTOP are the start and stop times of the exposure, in seconds
since the BAT trigger.  Exposure is the total exposure time, in
seconds, during that interval.

Filter   TSTART    TSTOP   Exposure       Mag  Err  Comments
     v      2687     2887        197     19.02 0.20
            8557     8757        197     18.66 0.21
     b      3072     3272        197    >20.5        3-sigma upper limit
            4507     4707        197     20.05 0.20
     u      2867   21,932       1601    >21.9        3-sigma upper limit
   uvw1     4097   21,019       1968    >21.8        3-sigma upper limit
   uvm2     3892   16,685       1590    >21.7        3-sigma upper limit
   uvw2     3482   15,250       1279    >21.7        3-sigma upper limit
  white     2708     7856        147     20.50 0.30
            4712     4912        197     19.41 0.10

The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E_{B-V} = 0.03 mag (Schlegel et al.,
1998, ApJS, 500, 525).  The photometry is on the UVOT photometric
system described in Poole et al. (2008, MNRAS, 383,627).  The
power-law decay index in the v band between 8557 and 15,864 s is
consistent with no decay.


GRB_name: GRB081024B
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8451
SUBJECT: GRB 081024B: VLA radio observation
DATE:    08/10/29 21:01:56 GMT
FROM:    Poonam Chandra at U Virginia/NRAO  <pc8s@virginia.edu>

P. Chandra (RMC), S. B. Cenko (Berkeley), D. A. Frail (NRAO) and
F. Harrison (Caltech) report on behalf of a larger GRB Collaboration:

"We used the Very Large Array to observe the Fermi-LAT detected
short hard burst GRB 081024B (GCN 8407) at a frequency of 8.46
GHz on 2008 Oct. 28.99 UT. The VLA field of view was centered at
RA: 21:31:37.63   Dec: +21:16:33.0 (J2000) for the observation.
We don't see any radio source in the VLA field of view. The map
rms is 38 uJy.

The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."


GRB_name: GRB081029A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8452
SUBJECT: GRB 081029, SMARTS optical/IR afterglow observations
DATE:    08/10/29 23:19:48 GMT
FROM:    Bethany Cobb at UC Berkeley  <bcobb@astro.berkeley.edu>

B. E. Cobb (UC Berkeley) reports:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained 
optical/IR imaging of the error region of GRB 081029 (GCN 8435, Sakamoto 
et al.) at three epochs with mid-exposure times of 2008-10-29 04:18 UT 
(2.57 hrs post-burst), 04:50 UT (3.10 hrs post-burst) and 05:21 UT (3.62 
post-burst).  At each epoch, several dithered images were obtained in each 
filter, with total summed exposure times of 180s in each of BRIJK and 120s 
in each of H and V.

The GRB afterglow (e.g. GCN 8436, Rykoff et al. and GCN 8437, Clemens et 
al.) is detected in all our filters:

filter  2.57 hrs 3.10 hrs 3.62 hrs
B       19.69+/-0.04  19.85+/-0.04    20.00+/-0.05
V       18.26+/-0.03   18.38+/-0.03    18.57+/-0.04
R       17.32+/-0.02   17.50+/-0.02    17.66+/-0.02
I       16.79+/-0.03    16.94+/-0.03    17.15+/-0.03
J       15.83+/-0.08    16.02+/-0.08    16.03+/-0.08
H       15.00+/-0.08    15.13+/-0.08    15.32+/-0.08
K       14.25+/-0.08   14.35+/-0.08    14.60+/-0.08

These preliminary magnitudes are calibrated using Landolt standard stars 
in the optical and 2MASS stars in the IR.

Between 2.57 hrs and 3.62 hours post-burst, the afterglow decays with an 
approximate optical decay rate of alpha~-0.9 (where afterglow flux
is proportional to t^alpha).


GRB_name: GRB080229B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8453
SUBJECT: Radio observation of GRB 080229b with ATCA
DATE:    08/10/31 17:40:33 GMT
FROM:    Aquib Moin at CIRA/ATNF  <aquib.moin@postgrad.curtin.edu.au>

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the SWIFT-XRT X-ray afterglow position of the GRB 080229b
(GCN 7354) at 4.8 and 8.456 GHz with the Australia Telescope Compact
Array (ATCA) on May 31, 2008 between 04:39:45 UT and 12:09:05 UT.

We did not detect a radio source at the XRT position of the GRB 080229b
afterglow (GCN 7354). The radio flux density at the GRB X-ray afterglow
position is -0.704 +/- 0.422 mJy at 4.8 GHz, and -0.012 +/- 0.255 mJy at
8.6 GHz (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See field image at:

http://astronomy.ivec.org/dokuwiki/doku.php/grb/grb_080229b_field_image 


GRB_name: GRB081024B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8454
SUBJECT: GRB 081024B: new Swift-XRT observations
DATE:    08/10/31 19:06:29 GMT
FROM:    Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>

C. Guidorzi, J. Mao, R. Margutti (INAF-OAB) on behalf
of the Swift-XRT team report:

Swift-XRT re-observed the field of the Fermi-LAT and Fermi-GBM
GRB 081024B (Omodei et al. GCN Circ. 8407; Connaughton et al GCN Circ. 8408)
from 2.75 to 6.1 days after the burst with a net exposure of 13 ks.
We combined this with our previous observation (Guidorzi et al. GCN Circ.
8416) for a resulting net exposure of 27 ks.
Source 2 identified in our earliest report (Guidorzi et al. GCN Circ. 8410)
as the only possibly fading source within the LAT error circle (GCN 8416)
and possibly associated with the variable optical object O2
(Cenko & Kasliwal GCN Circ. 8417; Kann et al. GCN Circ. 8423),
was finally detected with an average rate of (7.4 +- 2.2)e-4 counts/s
from 1.5 to 6.1 days. From the comparison with the first observation
(GCN 8410), in which the count rate was estimated to be (1.58 +- 0.54)e-3
counts/s, we estimate the probability of a constant rate source of 12%.
We also derived an upper limit to the possible power-law decay
index of alpha<0.8 from ~1 to ~5e5 s (90% confidence).
Therefore, at the moment we cannot confirm source 2 as the X-ray
afterglow candidate.

Further Swift-XRT observations are planned in order to clarify this issue.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081028A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8455
SUBJECT: GRB 081028: CrAO optical observations
DATE:    08/11/01 03:04:41 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

V. Rumyantsev,  V. Biryukov (CrAO), A. Pozanenko (IKI) report on behalf of
larger GRB follow-up collaboration:

We observed the error box of  Swift GRB 081028 (Guidorzi et al.,   GCN 8421)
in R and I bands on Oct. 28, and BVRI on Oct. 29-31 with Shajn telescope of
CrAO.  The observations started on Oct. 28 00:40:56 (UT), i.e. ~16 minutes
after burst onset. We clearly detect the afterglow (Clemens   et al.,  GCN
8424, Olofsson et al.,  GCN 8425) in initial images. Preliminary photometry
of combined images of Oct. 28 based on  USNO-B1.0 0923-0196037 star  RA
(J2000) = 08:07:36.55, Dec. (J2000) = +02:18:29.4, and assuming R2=15.89
I=15.45 is following:

T0+     Filter, Exposure, mag.,     err.
(d)             (s)
0.0206  R       23x60     21.62 +/- 0.07
0.0415  I       30x60     21.32 +/- 0.09
0.0640  I       30x60     21.43 +/- 0.09
0.0865  I       30x60     21.20 +/- 0.08
0.1091  I       30x60     20.66 +/- 0.05

Our photometry confirms re-brightening of the optical afterglow (Schady &
Guidorzi, GCN 8431) with sharp rise and maximum after ~9400 s which is
consistent with the time of the brightening observed in the XRT light curve
(Guidorzi et al., GCN  8429).

A finding chart of initial combined image in R can be found at
http://grb.rssi.ru/GRB081028/


GRB_name: GRB081024B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8456
SUBJECT: GRB 081024B: BTA deep optical observations
DATE:    08/11/01 10:35:39 GMT
FROM:    Vladimir Sokolov at SAO RAS  <sokolov@sao.ru>

T. Fatkhullin, A. Moskvitin (SAO-RAS Niznij Arkhyz), A.J. Castro-Tirado
(IAA-CSIC Granada), on behalf of a larger collaboration, report:


"We observed the field of the short duration GRB081024B (Omodei, GCNC 
8407; Connaughton and Briggs, GCNC 8408) in the Rc-band with the 6-m
telescope of the SAO RAS in Caucasus. In total two runs were performed
starting on 28 Oct 2008 (20:16 UT) and 29 Oct. 2008 (15:22 UT).
Integration times were 24 and 14 min respectively. Using SExtractor
software (Bertin & Arnouts 1996, A&AS 117, 393) and source "O1"
(Cenko & Kasliwal GCNC 8417; Kann et al. GCNC 8423) as a reference star,
we estimated the following magnitudes of the sources within the XRT error box:

         28 Oct.                     29 Oct.
O1: Rc = 20.55 +/- 0.04      Rc = 20.55 +/- 0.04    (from GCN 8423)
O2: Rc = 22.62 +/- 0.06      Rc = 22.65 +/- 0.06    (within 3.6 arcsec aperture)
O3: Rc = 23.19 +/- 0.15      Rc = 23.18 +/- 0.10    (within 3.6 arcsec aperture)
O4: Rc = 22.46 +/- 0.06      Rc = 22.53 +/- 0.06    (within 3.6 arcsec aperture)

The second epoch image (29 Oct.) shows that extended object "O2"
as noted from Palomar 200 inch Hale telescope observations (Cenko &
Kasliwal GCNC 8417) is most likely superposition of two objects.
These objects seem also to be extended in our image.
we conclude that all four sources showed no variability during the
time interval covered by our observations (including source "O2", whose
magnitude is comparable to the one reported by Cenko & Kasliwal).
As it is already mentioned by Guidorzi et al. (GCNC 8454) by means of
Swift/XRT observations, we can not confirm that the source "O2"
is fading in brightness, i.e. its relation to GRB081024B. This second
epoch image can be retrieved via anonymous FTP:
ftp://ftp.sao.ru/pub/grb/GRB081024B/GRB081024B_BTA_2nd_epoch.jpg ."


This message can be cited.


GRB_name: GRB081101A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8457
SUBJECT: Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
DATE:    08/11/01 12:21:04 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

M. Stamatikos (NASA/ORAU), S. D. Barthelmy (GSFC),
N. Gehrels (NASA/GSFC), N. P. M. Kuin (MSSL),
V. La Parola (INAF-IASFPA), C. B. Markwardt (CRESST/GSFC/UMD),
D. M. Palmer (LANL) and P. Romano (INAF-IASFPA) report on behalf of
the Swift Team:

At 11:46:31 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081101 (trigger=333320).  Swift did not slew because 
of the low merit value assignment because of the chance spatial coincidence
with the A0620-00 blackhole candidate source. 
The BAT on-board calculated location is 
RA, Dec 95.826, -0.082 which is 
   RA(J2000)  =  06h 23m 18s
   Dec(J2000) = -00d 04' 55"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single hard spike
with a duration of less than 128 msec.  The peak count rate
was ~7000 counts/sec (15-350 keV), at ~0 sec after the trigger. 
We can not rule out that this was from A0620-00, although the position 
is a very unlikely 18 arcmin away.  Thus, we believe this to be a gamma-ray
burst, or possibly a new SGR (although the spectrum is harder than typical
SGR bursts). 

Burst Advocate for this burst is M. Stamatikos (michael AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081101A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8458
SUBJECT: SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
DATE:    08/11/01 16:35:16 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), M. Stamatikos (GSFC/ORAU),
J. Kennea (PSU), V. Mangano (INAF-IASFPa), V. LaParola (INAF-IASFPA),
P. Romano (INAF-IASFPA), N. P. M. Kuin (MSSL)
(on behalf of the Swift-BAT/-XRT teams):
 
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 081101 (trigger #333320)
(Stamatikos, et al., GCN Circ. 8457).  The BAT ground-calculated position is
RA, Dec = 95.836, -0.112 deg, which is 
   RA(J2000)  =  06h 23m 20.7s 
   Dec(J2000) = -00d 06' 41.5" 
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 50%.
 
The mask-weighted light curve shows a single spike starting at ~T-0.05 sec,
peaking at ~T+0.1 sec, and ending by ~T+0.3 sec.
T90 (15-350 keV) is 0.20 +- 0.02 sec (estimated error including systematics).
 
The time-averaged spectrum from T+0.0 to T+0.2 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index -0.24 +- 1.12, 
and Epeak of 78 +- 34 keV (chi squared 62.8 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 6.2 +- 1.0 x 10^-8 erg/cm2
and the 1-sec peak flux measured from T-0.38 sec in the 15-150 keV band is
3.6 +- 0.5 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.25 +- 0.20 (chi squared 69.9 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level.

The BAT results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/333320/BA/

Swift/XRT began observing the field at 13:37:56 UT, 111 minutes after  
the BAT trigger, and observed the field in photon counting mode for 200 sec.
No point sources were detected in the field of view.  
Observations of this field are ongoing.

Given the short single spike form of the BAT lightcurve and the  
somewhat soft spectral values, this suggests that this is an SGR.
We can not rule out a GRB explanation of this event.


GRB_name: GRB081101A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8459
SUBJECT: SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
DATE:    08/11/01 23:09:44 GMT
FROM:    Vanessa Mangano at INAF-IASFPA  <vanessa@ifc.inaf.it>

V. La Parola, V. Mangano, B. Sbarufatti (INAF-IASF PA)
report on behalf of the Swift-XRT team

We have analysed the Swift-XRT follow-up observation of the source
(trigger #333320; Stamatikos, et al., GCN Circ. 8457)
started on 2008-11-01 14:49:13 UT (about 11 ks after the trigger).
In the first 3.4 ks of data no source is detected within the
BAT refined error circle (Barthelmy, et al., GCN Circ. 8458)
down to a limiting flux of 1.4e-13 erg cm^-2 s^-1.

This is an official product of the Swift-XRT team.


GRB_name: GRB081101A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8460
SUBJECT: GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
DATE:    08/11/02 06:27:35 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE), E. Bissaldi (MPE), M.S. Briggs (UAHuntsville) and C.
Kouveliotou (NASA/MSFC) report on behalf of the Fermi GBM Team: 

"At 11:46:32 UT on 01 November 2008, the Fermi GBM triggered and located an
event (trigger 247232793 / 081101491) which was also seen by SWIFT
(Stamatikos et al. 2008, GCN 8457, Barthelmy et al. 2008, GCN 8458). The GBM
on-ground location is consistent with the Swift position.

The GBM light curve shows a single peak with duration of about 224 ms. The
event is significantly detected with GBM between 40 - 200 keV. The
time-averaged spectrum from T0-0.103 s to T0+0.121 s is best fit by a single
power law with index -1.14 +/- 0.07 (chi squared 212 for 234 d.o.f.). The
event fluence (50-300 keV) in the same time interval is (1.6 +/- 0.08) E-07
erg/cm^2. 

The Swift team suggested that the event could be a possible new Soft Gamma
Repeater (SGR 0623-0006). The GBM spectrum is more consistent with that of a
faint short GRB; the lack of photons below 40 keV is rather unusual for an
SGR. 

The spectral analysis results presented above are preliminary; final results
will be published in the GBM GRB Catalog."


GRB_name: GRB081102A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8462
SUBJECT: GRB 081102: Swift detection of a burst
DATE:    08/11/02 18:10:16 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

T. N. Ukwatta (GSFC/GWU), S. D. Barthelmy (GSFC),
J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC),
C. Gronwall (PSU), C. Guidorzi (INAF-OAB),
S. T. Holland (CRESST/USRA/GSFC), W.B Landsman (GSFC),
V. Mangano (INAF-IASFPA), J. Mao (INAF-OAB),
P. T. O'Brien (U Leicester), D. M. Palmer (LANL),
P. Romano (INAF-IASFPA), B. Sbarufatti (INAF-IASFPA),
M. Stamatikos (NASA/ORAU) and H. Ziaeepour (UCL-MSSL) report on
behalf of the Swift Team:

At 17:44:39 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081102 (trigger=333427).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 331.182, +52.993 which is 
   RA(J2000)  = 22h 04m 44s
   Dec(J2000) = +52d 59' 36"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows multiple peaks
with a duration of about 40 sec.  The peak count rate
was ~1800 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 17:46:11.5 UT, 92.0 seconds after
the BAT trigger. Using promptly downlinked data we find a bright, fading
uncatalogued X-ray source located at RA, Dec 331.17357, 52.99345 which
is equivalent to:
   RA(J2000)  = 22h 04m 41.66s
   Dec(J2000) = +52d 59' 36.4"
with an uncertainty of 3.3 arcseconds (radius, 90% containment). This
location is 18 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
4.95e+21 cm^-2 (Kalberla et al. 2005). 

The initial flux in the 2.5 s image was 2.85e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White
(160-650 nm) filter starting 99 seconds after the BAT trigger. No
afterglow candidate has  been found in the initial data products. The
2.7'x2.7' sub-image covers all of the XRT error circle.  The image
is typically complete to about 18 mag. No  correction has been made
for the expected extinction corresponding to E(B-V) of  0.81. 

Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081102A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8463
SUBJECT: GRB 081102: OPTIMA-Burst optical upper limit
DATE:    08/11/02 21:32:24 GMT
FROM:    Alexander Stefanescu at MPE  <astefan@mpe.mpg.de>

A. Stefanescu, N. Primak, F. Schrey, G. Kanbach, A. Slowikowska, H.
Steinle, A. Updike and N. Lewandowski of the OPTIMA-Burst Team report
the following:

OPTIMA-Burst at the 1.3m Skinakas Observatory, of the University of
Crete and the Foundation for Research and Technolgy -- Hellas observed
the location of the XRT error-circle of GRB 081102 (GCN Circ 8462, T. N.
Ukwatta et al.), starting at 2008-11-02 18:02:23 UT (~18 min after the
burst).

We did not detect any source inside the XRT error-circle in several
co-added short (10-50s) white-light target acquisition frames taken
under adverse conditions.

Our limit is as follows:

t-t_0 (mid-exp)       t_exp     limit (white light)
1276s                 210s      18.5

Observations are ongoing.


GRB_name: GRB081102A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8464
SUBJECT: GRB 081102: MASTER VWF promt observation 
DATE:    08/11/02 22:34:37 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

MASTER-Net Team (http://observ.pereplet.ru):

V. Lipunov, V.Kornilov,  E.Gorbovskoy,
A.Belinski, N.Shatskiy, N.Tyurina, D.Kuvshinov, P.Balanutsa
Sternberg Astronomical Institute, Moscow State University

A. Tlatov, I.Golubov
Kislovodsk Solar Station of the Pulkovo observatory

V.Krushinski, I.Zalognikh
Ural State University, Kourovka


S.Yazev, K.Ivanov
Irkutsk State University


MASTER Very Wide Field Camera located at Kislovodsk (2000 m)
(http://apollo.sai.msu.ru/, D=50 mm, 4000 square degrees, 35'' per pix) 
has observed the Swift-BAT GRB081102 error box  (Ukwatta et al., GCN Circ 
8642) with 5s exposures  starting before, during and after the GRB time.

These unfiltered images are calibrated relative to USNO A2.0 (R).
The limit of the each image is aboute 11.1 (S/N=3).

The reduction is continuing.

mailto: lipunov@sai.msu.ru


GRB_name: GRB080229A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8465
SUBJECT: Radio observation of GRB 080229a with ATCA
DATE:    08/11/03 01:29:59 GMT
FROM:    Aquib Moin at CIRA/ATNF  <aquib.moin@postgrad.curtin.edu.au>

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the BAT refined position of the GRB 080229a (GCN 7338) at
4.8 and 8.456 GHz with the Australia Telescope Compact Array (ATCA) on
May 31, 2008 between 08:18:55 UT and 13:38:25 UT.

We did not detect a radio source at the BAT position of the GRB 080229a
(GCN 7338). The radio flux density at the GRB position is -0.053 +/-
0.175 mJy at 4.8 GHz, and -0.383 +/- 0.356 mJy at 8.6 GHz (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See field image at:

http://cira.ivec.org/dokuwiki/doku.php/grb/grb_080229a_field_image 

Please note: http://astronomy.ivec.org is now http://cira.ivec.org


GRB_name: GRB080218B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8466
SUBJECT: Radio observation of GRB 080218b with ATCA
DATE:    08/11/03 01:41:02 GMT
FROM:    Aquib Moin at CIRA/ATNF  <aquib.moin@postgrad.curtin.edu.au>

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the SWIFT-BAT refined position of the GRB 080218b (GCN 7325)
at 4.8 and 8.456 GHz with the Australia Telescope Compact Array (ATCA)
on May 31, 2008 between 04:24:45 UT and 10:15:15 UT.

We did not detect a radio source at the BAT position of the GRB 080218b
(GCN 7325). The radio flux density at the GRB position is -0.286 +/-
0.252 mJy at 4.8 GHz, and -0.350 +/- 0.271 mJy at 8.456 GHz (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See field images at:

http://cira.ivec.org/dokuwiki/doku.php/grb/grb_080218b_field_image_at_4.8_ghz

http://cira.ivec.org/dokuwiki/doku.php/grb/grb_080218b_field_image_at_8.456_ghz


GRB_name: GRB081102A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8467
SUBJECT: GRB 081102: Enhanced Swift-XRT position
DATE:    08/11/03 05:12:54 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 4108 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 081102, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 331.1724, +52.9942 which is equivalent
to:

RA (J2000): 22h 04m 41.38s
Dec (J2000): +52d 59' 39.3"

with an uncertainty of 1.5 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081102A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8468
SUBJECT: GRB 081102: Swift-BAT refined analysis
DATE:    08/11/03 13:22:28 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

E. E. Fenimore (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+962 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 081102 (trigger #333427)
(Ukwatta, et al., GCN Circ. 8462).  The BAT ground-calculated position is
RA, Dec = 331.178, 52.991 deg, which is 
   RA(J2000)  =  22h 04m 42.6s 
   Dec(J2000) = +52d 59' 27.7" 
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 36%.
 
The mask-weighted light curve shows two overlapping peaks, the first starting
at ~T-20 sec, peaking at ~T-15 sec, and hitting a minimum between the two
peaks at ~T-7 sec.  The second peak peaks at ~T+1 sec, and returns to background
at ~T+90 sec.  T90 (15-350 keV) is 63 +- 16 sec (estimated error
including systematics).
 
The time-averaged spectrum from T-20.2 to T+62.8 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.73 +- 0.13.  The fluence in the 15-150 keV band is 2.3 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.08 sec in the 15-150 keV band
is 1.4 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/333427/BA/


GRB_name: GRB081102A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8469
SUBJECT: GRB 081102:  Swift/UVOT refined analysis
DATE:    08/11/03 15:13:14 GMT
FROM:    Stefan Immler at NASA/GSFC  <stefan.m.immler@nasa.gov>

S. Immler (GSFC/CRESST/UMCP) and T. N. Ukwatta (GSFC/GWU) report on the 
behalf of the Swift UVOT team:

The Swift Ultra-Violet/Optical Telescope (UVOT) began observing GRB 
081102 (trigger 333427) 83 seconds after the BAT trigger (Ukwatta et 
al., GCN Circ. 8462). No afterglow is detected at the enhanced XRT 
position (Osborne et al., GCN Circ. 8467) in the initial v-filter 
finding chart or subsequent images. The limiting magnitudes (3-sigma in 
3" radius apertures) in each of the UVOT filters are as follows:

Filter  T_start(s)  T_stop(s)  Exp(s)  Mag UL (3sig)

white      100       19051       1246     >21.9
v           83      35803       1423     >20.3
b          433      24833       1808     >21.3
u          408     30614       2717     >21.3
uvw1       383      29977       2922     >21.1
uvm2      359      36395       2701     >20.9
uvw2      309      34890       1434     >20.7

The values quoted above are in the UVOT photometric system (Poole et al. 
2008, MNRAS, 383, 627). They are not corrected for the high (and 
unreliable) Galactic extinction at the low Galactic latitude of the 
burst of <5 degrees.


GRB_name: GRB081102A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8470
SUBJECT: GRB 081102: Swift-XRT refined analysis
DATE:    08/11/03 15:16:22 GMT
FROM:    Boris Sbarufatti at INAF-IASF-Pa  <sbarufatti@ifc.inaf.it>

V. Mangano, B. Sbarufatti, V. La Parola (INAF-IASF Pa), T. Ukwatta  
(GSFC/GWU)
report on behalf of the Swift-XRT team:

Swift-XRT began observing the field of GRB 081102 (trigger 333427,  
Ukwatta et
al., GCN circ.8462) at 17:46:11.5 UT, 92.0 seconds after the BAT  
trigger.
We analysed data from the first 10 orbits, consisting of 151 s in  
Windowed
Timing mode, from T+98 s to T+251s and 14 ks in Photon Counting mode,  
from
T+251s to T+42.1 ks. The lightcurve is best fit by a broken powerlaw  
model
with slopes alpha_1 = -2.35 +/- 0.15 and alpha_2= -1.22 (-0.11 +0.22)  
and
break time T_break = T+560 (-160 +500)s. After the break, we observe  
a strong
flare at T+960 (-11+21) s with decay time 157 +/-15 s.

The WT spectrum is best fit by a simple absorbed powerlaw with photon  
index
2.7 +/- 0.1 and an absorbing column consistent with the Galactic  
value of
4.9E21 cm^-2 (Kalberla et al. 2005). The observed (unabsorbed) flux  
in the
0.3 - 10 keV band is 4.0E-10 (1.3E-9) erg cm^-2 s^-1. The PC spectrum  
is best
fit by a simple absorbed powerlaw with photon index 1.97 +/- 0.1 and an
absorbing column consistent with the Galactic value. The observed  
(unabsorbed)
flux in the 0.3 - 10 keV band is 1.1 (1.8)E-11 erg cm^-2 s^-1. The  
countrate to flux
conversion factor is 7.1E-11.

The predicted countrate for November 3, 17:45 UT (T+ 24h) is 1.3E-3  
counts/s
equivalent to a flux of 9.2E-14 erg cm^-2 s^-1.

All quoted errors are at 90% confidence level.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081102A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8471
SUBJECT: GRB 081102: MASTER prompt optical limit
DATE:    08/11/03 20:06:42 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

MASTER-Net Team (http://observ.pereplet.ru):

V. Lipunov, V.Kornilov,  E.Gorbovskoy,
A.Belinski, N.Shatskiy, N.Tyurina, D.Kuvshinov, P.Balanutsa
Sternberg Astronomical Institute, Moscow State University

A. Tlatov, A.Parkhomenko
Kislovodsk Solar Station of the Pulkovo observatory

V.Krushinski, I.Zalognikh
Ural State University, Kourovka


S.Yazev, K.Ivanov
Irkutsk State University


MASTER Very Wide Field Camera located at Kislovodsk (2000 m)
(http://apollo.sai.msu.ru/, D=50 mm, 4x1000 square degrees, 35'' per pix) 
has observed the Swift-BAT GRB081102 error box  (Ukwatta et al., GCN Circ 8642) 
with 5s exposures during all night without windows between images. 
There are two  separeted (~702m) mount with double cameras.

Now we present results from North camera.

These unfiltered images are calibrated relative to Tycho stars (V).
We do not detect any new source at the XRT position
reported in GCN Circ. 8467 ( Osborne et al.) brighter than 12.4 mag 
before and after trigger time.
The photometry results +-4 min around trigger time:


  T-T_trigger            m_lim (S/N=3)         Exposure         Coadd

-255s... 0... 255 s       11.6                  5s              no 
-2min...0...+2 min        12.2                 30s               6
-2min...0...+2 min        12.4                 60s              12

The optical fluence during the 60s-GRburst is limited by <= 6x10_-9 
erg/cm_2    including 2.5 magnitude  absorbtion (Ukwatta et al., Circ 
8462). The BAT-fluence is aboute 3 10_-6 erg/cm_2 (15-150 Kev) 
(http://gcn.gsfc.nasa.gov/notices_s/333427/BA/).
So

Optical Fluence/Gamma-Fluence ~ < 1/500

Same ratio for GRB080319B is ~ 1/200 (Naked Eye GRB).

The  light curve  is available at
http://observ.pereplet.ru/images/GRB081102/lc1.png


The  video  are available at
http://observ.pereplet.ru/images/GRB081102/grb.gif
You can see 200 sets.
Note: the GRB was at the edge of the FOW.

The reduction is continuing.

mailto: lipunov@sai.msu.ru


GRB_name: GRB080130A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8472
SUBJECT: Radio observation of GRB 080130 with ATCA
DATE:    08/11/04 03:26:01 GMT
FROM:    Aquib Moin at CIRA/ATNF  <aquib.moin@postgrad.curtin.edu.au>

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the BAT refined position of the GRB 080130 (GCN 7248) at 4.8
and 8.456 GHz with the Australia Telescope Compact Array (ATCA) on May
31, 2008 between 09:15:05 UT and 13:07:05 UT.

We did not detect a radio source at the BAT position of the GRB 080130
(GCN 7248). The radio flux density at the GRB position is -0.153 +/-
0.246 mJy at 4.8 GHz, and 0.113 +/- 0.284 mJy at 8.6 GHz (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See field image at:

http://cira.ivec.org/dokuwiki/doku.php/grb/grb_080130_field_image 


GRB_name: GRB081104A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8473
SUBJECT: GRB 081104: Swift detection of a burst
DATE:    08/11/04 09:53:20 GMT
FROM:    Ann M. Parsons at NASA/GSFC/Swift  <parsons@milkyway.gsfc.nasa.gov>

A. M. Parsons (GSFC), A. P. Beardmore (U Leicester),
P. J. Brown (PSU), P. A. Evans (U Leicester), C. Gronwall (PSU),
C. Guidorzi (INAF-OAB), S. T. Holland (CRESST/USRA/GSFC),
N. P. M. Kuin (MSSL), V. La Parola (INAF-IASFPA),
V. Mangano (INAF-IASFPA), J. Mao (INAF-OAB),
P. T. O'Brien (U Leicester), J. P. Osborne (U Leicester),
K. L. Page (U Leicester), P. Romano (INAF-IASFPA),
T. N. Ukwatta (GSFC/GWU) and H. Ziaeepour (UCL-MSSL) report on behalf
of the Swift Team:

At 09:34:42 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081104 (trigger=333666).  
The BAT on-board calculated location is 
RA, Dec 100.485, -54.732 which is 
   RA(J2000) = 06h 41m 56s
   Dec(J2000) = -54d 43' 55"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multiple peaked
structure with a duration of about 30 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~10 sec after the trigger. 

Due to an observing constraint, Swift will not slew until 
T0+40.5 minutes. There will be no XRT or UVOT data until
this time. 

Burst Advocate for this burst is A. M. Parsons (parsons AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081104A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8474
SUBJECT: GRB 081104: Swift-XRT position
DATE:    08/11/04 10:42:53 GMT
FROM:    Vanessa Mangano at INAF-IASFPA  <vanessa@ifc.inaf.it>

V. Mangano, V. La Parola (INAF-IASF PA), P. Evans (U. Leicester)
report on behalf the Swift XRT Team:


Swift slewed to the target (trigger=333666, Parsons et al.,
GCN Circ. 8473) at about 10:14:00 UT.
Using promptly downlinked XRT data we find an uncatalogued
source located at RA,Dec = 100.4835, -54.7211
which is equivalent to:

RA  (J2000) =  06 41 56.04
DEC (J2000) =  -54 43 15.9

with an uncertainty of 4.04 arcsec (radius, 90% containment).
This location is 39.4 arcsec from the BAT position, inside the BAT
error circle.

This is an official product of the Swift XRT Team.


GRB_name: GRB081104A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8475
SUBJECT: GRB 081104 : Faulkes Telescope South observations
DATE:    08/11/04 13:58:03 GMT
FROM:    Andrea Melandri at Liverpool John Moores U  <axm@astro.livjm.ac.uk>

A. Melandri, D.F. Bersier, M. Burgdorf, C.G. Mundell, R.J. Smith,
I.A. Steele (Liverpool JMU) on behalf of a larger collaboration
report:


On 2008 November 04 on 12:13 UT we observed the field of GRB 081104
(trigger = 333666, Parsons et al., GCN 8473) with the robotic 2m
Faulkes Telescope South located in Australia.

We do not detect any fadind optical source within the XRT error circle
(Mangano et al., GCN 8474) down to the following limit:


   Dt_mid    T_exp     Filter      Mag_lim
    [hr]     [min]
===========================================
    2.89     30.0        R         > 21.9
===========================================


Limiting magnitude has been estimated using the R2 magnitude of the
USNO-B1 catalogue. The reported value is not corrected for the
Galactic extinction.


GRB_name: GRB081102A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8476
SUBJECT: Fermi Detection of GRB 081102
DATE:    08/11/04 16:32:24 GMT
FROM:    Chryssa Kouveliotou at MSFC  <chryssa.kouveliotou@nasa.gov>

C. Kouveliotou (NASA/MSFC) and M.S. Briggs (UAHuntsville) report on
behalf of the Fermi GBM Team:

At 17:44:21.6 UT on 02 November 2008, the Fermi GBM triggered and
located an event (trigger 247340662 / 081102739) which was also seen by
SWIFT (Ukwata et al. 2008, GCN 8462). The GBM on-ground location is
consistent with the Swift position; the GBM trigger time is 17.4 s
earlier than the Swift trigger. 

The GBM light curve shows a multiple peak event (three and possibly four
peaks) with T90= 88 s (50-300 keV). The time-averaged spectrum from
T0-2.048 s to T0+46.01 s is best fit by a exponentially cutoff power law
model with Epeak = 88.7 +/- 8.3 keV, and index 0.0 +/- 0.3 (chi squared
278 for 238 d.o.f.). The event fluence (50-300 keV) in this time
interval is (2.1 +/- 0.05)E-06 erg/cm^2. A Band function fit the
spectrum equally well (chi squared 276 for 237 d.o.f.) with Epeak=72 +/-
13, alpha = 0.44 +/- 0.58 and beta = -2.36 +/- 0.32. 

The spectral analysis results presented above are preliminary; final
results will be published in the GBM GRB Catalog.


GRB_name: GRB081104A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8478
SUBJECT: GRB081104: Swift/UVOT Upper Limits
DATE:    08/11/04 20:35:43 GMT
FROM:    Peter Brown at PSU  <pbrown@astro.psu.edu>

P. J. Brown, C. A. Swenson (PSU), S. T. Holland, and A. M. Parsons (GSFC),
on behalf of the Swift/UVOT team.

The Swift Ultra-Violet/Optical Telescope (UVOT) began settled
observations of GRB 081104 (trigger 333666) 2638 seconds after the BAT
trigger (Parsons et al., GCN Circ. 8473). No afterglow is detected at the
XRT position (Mangano et al., GCN Circ. 8474) in any filter.
The limiting magnitudes (3-sigma in 5" radius apertures) in each
of the UVOT filters are as follows:

Filter  T_start(s)  T_stop(s)  Exp(s)  Mag UL (3sig)

white     2638      3882       209     >21.1
v         2794      9582       1082    >20.5
b         3614      3814       197     >20.4
u         3409      3609       197     >20.1
uvw1      3204      3404       197     >19.8
uvm2      2999      9874       479     >20.1
uvw2      2788      5368       197     >19.9

The values quoted above are in the UVOT photometric system (Poole et al.
2008, MNRAS, 383, 627).  They are not corrected for the expected
Galactic extinction corresponding to a reddening of E(B-V)=0.11 mag in
the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB081104A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8479
SUBJECT: GRB 081104: Swift-BAT refined analysis
DATE:    08/11/04 22:39:17 GMT
FROM:    Ann M. Parsons at NASA/GSFC/Swift  <Ann.M.Parsons@nasa.gov>

H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC),C. B. Markwardt (GSFC/UMD),
K. McLean (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+962 sec from the recent telemetry
downlink,
we report further analysis of BAT GRB 081104 (trigger #333666)
(Parsons, et al., GCN Circ. 8473).  The BAT ground-calculated position is
RA, Dec = 100.500, -54.722 deg which is
   RA(J2000)  =  06h 42m 00.0s
   Dec(J2000) = -54d 43' 17.4"
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 32%.
 
The BAT mask-weighted light curve shows a single FRED peak.
T90 (15-350 keV) is 59.1 +- 13.9 sec (estimated error including
systematics).
 
The time-averaged spectrum from T-23.5 to T+51.2 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.00 +- 0.14.  The fluence in the 15-150 keV band is 2.0 +- 0.2 x 10^-06
erg/cm2.
The 1-sec peak photon flux measured from T+13.54 sec in the 15-150 keV band
is 1.0 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/333666/BA/


GRB_name: GRB081104A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8480
SUBJECT: GRB 081104: Enhanced Swift-XRT position
DATE:    08/11/05 08:02:38 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 4796 s of XRT Photon Counting mode data and 6 UVOT
images for GRB 081104, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 100.4886, -54.7199 which is equivalent
to:

RA (J2000): 06h 41m 57.26s
Dec (J2000): -54d 43' 11.5"

with an uncertainty of 1.6 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081104A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8481
SUBJECT: GRB 081104: refined XRT analysis
DATE:    08/11/05 11:11:44 GMT
FROM:    Vanessa Mangano at INAF-IASFPA  <vanessa@ifc.inaf.it>

V. Mangano, V. La Parola, B. Sbarufatti (INAF-IASF PA)
report on behalf the Swift-XRT Team:

Swift XRT follow-up observation of the field of GRB 081104
(trigger=333666, Parsons et al., GCN Circ. 8473) started on
2008 11 04 at 10:18:45 UT (about 40 min after the trigger).

We have analysed the first four orbits of PC mode XRT data
accumulated from T+2640 s to T+22153 s (6.5 ks exposure).
The light curve of the X-ray source given in Mangano e. at,
GCN Circ. 8474 shows a power-law decay with slope -1.0 +/- 0.2,
with an initial count rate at the level of 0.1 counts/s.
If decaying at this rate the source will reach a count rate
level of 3.e-3 counts/s at T+24 hours.

The average spectrum of the source have been fitted with Cash
statistics. It can be modeled with a highly absorbed power law,
with NH=(1.5 +/ -0.4)e22 cm^-2 (significantly in excess with respect
to the Galactic absorption along the line of sight, of 7.0e20  cm^-2;
Kalberla et al. 2005) and a photon index of 5.2 +/- 1.0
(C-statistic=84.4 with 93 bins).


With the power law fit, the average observed (unabsorbed) flux
in the 0.3-10 keV energy range is of 8.0e-13 (1.9e-10) erg cm^-2 s^-1.

This is an official product of the Swift-XRT Team.


GRB_name: GRB081104A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8482
SUBJECT: GRB 081104: GROND Detection of the Optical/NIR Afterglow Candidate?
DATE:    08/11/05 11:23:12 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

C. Clemens, T. Kruehler, J. Greiner, R. Filgas, A. Yoldas (all MPE Garching),
A. Kupcu Yoldas (ESO) and G. Szokoly (Eoetvoes Univ., Budapest) 
report on behalf of the GROND team:
 
We observed the field of GRB 081104 (Swift trigger 333666; Parsons et al., GCN
#8473) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 
120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla Observatory
(Chile). 
  
Observations started at 07:43 UT on November 5th, 2008, 22.1 hr after the GRB
trigger. They were performed at an average seeing of 1.0" and at an average
airmass of 1.1.

We found a single point source at the edge of the astrometrically 
corrected 1.6'' Swift-XRT error circle reported by Beardmore et al. 
(GCN #8480) at
  
RA (J2000) = 06h 41m 57.13s  
DEC (J2000) = -54d 43' 09.9''
  
with an uncertainty of 0.5".
  
Based on the first 25 min of total exposures in g'r'i'z' and 20 min in
JHK, we estimate preliminary magnitudes (all in AB system) of
  
g' ~ 22.7 mag, 
r' ~ 22.6 mag, 
i' ~ 21.8 mag, 
z' ~ 21.7 mag, 
J ~ 21.2 mag,
H > 21.1 mag and
K > 20.0 mag

with errors of +/- 0.2. These magnitudes are calibrated against GROND
zeropoints as well as 2MASS field stars, and are not corrected for the
galactic foreground extinction of E(B-V)= 0.1
  
The extinction-corrected spectral energy distribution is only marginally
consistent with a power law, so at present (without proper calibration)
we cannot distinguish between a foreground star, an afterglow, or a host.
No statement about variability can be made at this point either. 

We note that a very faint object is also visible on the POSS-IIN plate at 
this location.


GRB_name: GRB081025A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8483
SUBJECT: GRB 081025: Fermi GBM observation
DATE:    08/11/05 17:11:18 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE) and E. Bissaldi (MPE)
report on behalf of the Fermi GBM Team: 

"At 08:23:05.29 UT on 25 October 2008, the Fermi GBM triggered and located
GRB 081025 (trigger 246615786 / 081025349) which was also detected by the
SWIFT-BAT Slew Survey (A. Copete et al. 2008, GCN 8409) and followed up by
SWIFT-XRT (J. Mao et al. 2008, GCN 8411). The GBM on-ground location is
consistent with the Swift position. 

The GBM light curve shows a multipeaked structure with a duration (T90) of
about 45 s (8-1000 keV). The time-averaged spectrum from T0-1.536 s to 
T0+24.064 s is best fit by an exponentially cutoff power law model with 
Epeak = 251 +/- 25 keV, and index -0.35 +/- 0.13 (chi squared 736 for 700 
d.o.f.). The event fluence (8-1000 keV) in this time interval is 
(7.1 +/- 0.5)E-06 erg/cm^2. The 1-sec photon flux measured from T+2.56 sec
in the 8-1000 keV band is 4.50 +/- 0.22  ph/cm2/sec. A Band function fit
the spectrum equally well (chi squared 732 for 699 d.o.f.) with 
Epeak= 200 +/- 33 keV, alpha = 0.15 +/- 0.22 and beta = -2.05 +/- 0.25. 

The spectral analysis results presented above are preliminary; final results

will be published in the GBM GRB Catalog."


GRB_name: GRB081105A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8484
SUBJECT: GRB 081105 Swift/BAT and IPN Localization
DATE:    08/11/06 01:00:17 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <jayc@milkyway.gsfc.nasa.gov>

J. Cummings, S. Barthelmy, N. Gehrels, H. Krimm, and D. Palmer, 
on behalf of the Swift-BAT team

S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,
K. Hurley, and T. Cline on behalf of the Konus-Wind team,

K. Yamaoka, M. Ohno, Y. Fukazawa, T. Takahashi, M. Tashiro, Y. Terada,
T. Murakami, and K. Makishima on behalf of the Suzaku WAM team

A. von Kienlin, G. Lichti, and A. Rau, on behalf of the
INTEGRAL SPI-ACS GRB team,

and M. Marisaldi, F. Fuschino, M. Galli, C. Labanti,
E. Del Monte, F. Lazzarotto, L. Pacciani, and P. Soffitta
on behalf of the AGILE team

At 2008-11-05 T0=48372.403 s UT (13:26:12.403), a long soft GRB,
GRB 081105 triggered Konus/Wind. The IPN was informed, and Swift/BAT,
AGILE-MCAL, Suzaku/WAM, and INTEGRAL/SPI-ACS reported coincident
rate increases. Ground analysis of BAT data (trigger #333811) yielded 
a significant image peak that was found to be coincident with the IPN 
timing triangulation annulus. The location of the burst was
RA, Dec 3.966, 3.454, uncertainty radius of 2.5 arcmin, which is

   RA(J2000) = 00h 15m 51.8s
   Dec(J2000) = +03d 27' 14"

The source was found onboard, but not with high enough significance
to trigger an automatic burst response. The partial coding was only
2.5%.

The burst was a single peak, about 10 seconds long.

A Swift TOO has been requested and approved. The Swift narrow-field
instruments should begin observing the burst at about 04:30 UT, 15
hours after the burst. 


GRB_name: GRB080516A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8485
SUBJECT: Radio observation of GRB 080516 with ATCA
DATE:    08/11/06 08:11:48 GMT
FROM:    Aquib Moin at CIRA/ATNF  <aquib.moin@postgrad.curtin.edu.au>

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the BAT refined position of the GRB 080516 (GCN 7736) at 4.8
GHz with the Australia Telescope Compact Array (ATCA) on June 01, 2008
between 03:54:25 UT and 07:45:35 UT.

We did not detect a radio source at the BAT position of the GRB 080516
(GCN 7736). The radio flux density at the GRB position is -0.128 +/-
0.224 mJy at 4.8 GHz (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See field image at:

http://cira.ivec.org/dokuwiki/doku.php/grb/grb_080516_field_image 


GRB_name: GRB081101B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8486
SUBJECT: GRB 081101B: Fermi GBM detection
DATE:    08/11/06 12:17:16 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs@mpe.mpg.de>

E. Bissaldi (MPE) and A. von Kienlin (MPE)
report on behalf of the Fermi GBM Team: 


"At 12:45:24.08 UT on November 01, 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081101B (trigger 247236325 / 081101532).
The on-ground calculated location, using the Fermi GBM
trigger data, is RA = 212.5 deg, Dec = -31.1 deg
(equivalent to J2000 14h 10m, -31d 06'), with a statistical
uncertainty of 1.9 degrees (radius, 1-sigma containment;
there is additionally a systematic error which is currently
estimated to be 2 to 3 degrees). The angle from the
Fermi LAT boresight is 116 degrees.

This GRB consists of one main emission phase comprising
several overlapping pulses, with an estimated T90 (8-1000 keV)
of about 8 s and T50 (8-1000 KeV) of about 5 s.
The time-averaged spectrum from T0 to T0+7.680 s
is best fit by a power law function with an exponential
high energy cutoff. The power law index is -0.62 +/- 0.05
and the cutoff energy, parameterized as Epeak,
is 550 +/- 30 keV. The event fluence (8-1000 keV)
in this time interval is (1.60 +/- 0.03)E-05 erg/cm^2.
The 1-sec photon flux measured starting from T0+1.536 s
in the 8-1000 keV band is 10.3 +/- 0.3 ph/s/cm^2.


The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081105A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8487
SUBJECT: Swift-XRT observations of GRB 081105
DATE:    08/11/06 15:41:23 GMT
FROM:    Andy Beardmore at U Leicester  <apb@star.le.ac.uk>

A.P. Beardmore (U. Leicester) and J. Cummings (GSFC/UMBC)
report on behalf of the Swift-XRT  team.

The Swift-XRT started observing the field of the Swift-BAT and IPN
localization GRB 081105 (Cummings et al., GCN 8484) at
2008-11-06 05:18:07(UT), 15.8 hours after the trigger.

In an exposure of 5ks we detect an X-ray source within the BAT error
circle at RA, Dec = 3.95224, 3.47098, which is
RA  (J2000) =  00:15:48.5
Dec (J2000) = +03:28:15.5
with an uncertainty of 4.8 arcsec (radius, 90 percent confidence).

The observed count rate is (7.6+/-2.0)e-3 count/s. At this stage we cannot
tell whether the source is fading. Further Swift observations are planned.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081105A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8488
SUBJECT: UVOT/Swift observations of GRB081105
DATE:    08/11/06 16:07:53 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps@mssl.ucl.ac.uk>

P.A. Curran (UCL-MSSL), P. Schady (UCL-MSSL) and J. Cummings (GSFC/UMBC), 
on behalf of the Swift/UVOT team.

The Swift Ultra-Violet/Optical Telescope (UVOT) began settled observations 
of the Swift-BAT and IPN localization GRB 081105 (#333811; Cummings et 
al., GCN 8484) ~16 hours after the BAT trigger. No afterglow is detected 
at the XRT position (Beardmore et al., GCN 8487) in any filter. The 
3-sigma limiting magnitudes in each of the observed UVOT filters are as 
follows:

Filter  T_start(dys) Exp(s)  Mag UL (3sig)

white     0.67        159     > 20.76
v         0.81        630     > 19.92
b         0.66        885     > 21.05
u         0.74        224     > 19.92
uvw1      0.73        886     > 20.75
uvw2      0.89        886     > 21.02

The values quoted above are in the UVOT photometric system (Poole et al. 
2008, MNRAS, 383, 627).  They are not corrected for the expected Galactic 
extinction corresponding to a reddening of E(B-V)=0.03 mag in the 
direction of the burst (Schlegel et al. 1998).


GRB_name: GRB081105A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8489
SUBJECT: GRB 081105: Observations from OSN
DATE:    08/11/06 21:59:26 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (ESO, Santiago), F. Aceituno &
A. J. Castro-Tirado (IAA-CSIC, Granada) report on
behalf of a larger collaboration:

We have observed the field of GRB 081105
(Cummings et al. GCNC 8484) with the 1.5m OSN
telescope in R and I bands. We do not detect any
source within the XRT error box (Beardmore et
al. GCNC 8487). The mean times and 3-sigma
limits of the observations are the following:
t-t0(days)    Band     Limit
1.2454        R        > 21.3
1.2499        I        > 20.7
Photometry is based on the star 0934-0003777 of
USNO-B1.0 catalogue (R.A.: 3.953112, Dec.:
+3.463859), assuming R=17.11 and I=16.54.


GRB_name: GRB080520A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8490
SUBJECT: Radio observation of GRB 080520 with ATCA
DATE:    08/11/07 01:40:35 GMT
FROM:    Aquib Moin at CIRA/ATNF  <aquib.moin@postgrad.curtin.edu.au>

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the BAT refined position of the GRB 080520 (GCN 7761) at 4.8
GHz with the Australia Telescope Compact Array (ATCA) on June 01, 2008
between 08:41:15 UT and 09:45:25 UT.

We did not detect a radio source at the BAT position of the GRB 080520
(GCN 7761). The radio flux density at the GRB position is 0.297 +/-
0.217 mJy at 4.8 GHz (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See field image at:

http://cira.ivec.org/dokuwiki/doku.php/grb/grb_080520_field_image 


GRB_name: GRB080523A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8491
SUBJECT: Radio observation of GRB 080523 with ATCA
DATE:    08/11/07 01:47:29 GMT
FROM:    Aquib Moin at CIRA/ATNF  <aquib.moin@postgrad.curtin.edu.au>

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the BAT refined position of the GRB 080523 (GCN 7772) at 4.8
GHz with the Australia Telescope Compact Array (ATCA) on June 01, 2008
between 04:12:15 UT and 06:37:35 UT.

We did not detect a radio source at the BAT position of the GRB 080523
(GCN 7772). The radio flux density at the GRB position is -0.069 +/-
0.172 mJy at 4.8 GHz (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See field image at:

http://cira.ivec.org/dokuwiki/doku.php/grb/grb_080523_field_image 


GRB_name: GRB081105A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8492
SUBJECT: GRB 081105: GROND Upper Limits
DATE:    08/11/07 07:53:48 GMT
FROM:    Christian Clemens at MPE  <cclemens@mpe.mpg.de>

C. Clemens, R. Filgas, J. Greiner, T. Kruehler, A. Yoldas (all MPE Garching), 
A. Kupcu Yoldas (ESO) and G. Szokoly (Eoetvoes Univ., Budapest) report on 
behalf of the GROND team:

We observed the field of GRB 081105 (Swift trigger #333811; Cummings et al., 
GCN #8484) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, 
PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla Observatory 
(Chile).

Observations started at 02:01 UT on November 6th, 2008, 12.6 hr after the GRB 
trigger with 23.0 min of total exposures in g'r'i'z' and 24.0 min in JHK. 
They were performed at an average seeing of 1.4" and at an average airmass of 
1.2.

As Ugarte Postigo et al. (GCN #8489), we do not detect any object within the 
4.8'' Swift-XRT error circle reported by Beardmore et al. (GCN #8487) down to 
the following upper limits (all in AB system) of:

g' > 23.3 mag,
r' > 23.2 mag,
i' > 22.5 mag,
z' > 22.3 mag,
J > 21.6 mag,
H > 21.0 mag and
K > 20.0 mag.

These upper limits are derived based on calibrating the images against the 
GROND zeropoints as well as 2MASS field stars.


GRB_name: GRB081104A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8493
SUBJECT: GRB 081104: GROND found no Optical/NIR Afterglow
DATE:    08/11/07 09:38:11 GMT
FROM:    Christian Clemens at MPE  <cclemens@mpe.mpg.de>

C. Clemens, T. Kruehler, J. Greiner (all MPE Garching) and G. Szokoly 
(Eoetvoes Univ., Budapest) report on behalf of the GROND team:
 
We observed the field of GRB 081104 for a second time at 04:29 UT on November 
6th, 2008, 42.9 hr after the GRB trigger with 73.0 min of total exposures in 
g'r'i'z' and 64.0 min in JHK. Observations were performed at an average 
seeing of 1.7".

We still detect the previously reported source (Clemens et al., GCN #8482) 
with magnitudes identical within the errors to our first epoch observations.

Therefore, this object is most likely not the afterglow of GRB 081104.


GRB_name: GRB081107A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8494
SUBJECT: GRB 081107: Fermi GBM detection
DATE:    08/11/07 15:51:17 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE) and E. Bissaldi (MPE) 
report on behalf of the Fermi GBM Team: 

"At 07:42:01.11 UT on 07 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081107 (trigger 247736522 / 081107321).
The on-ground calculated location, using the GBM trigger 
data, is RA = 47.7, DEC = +17.0 (J2000 degrees, 
equivalent to 03h 11m, 17d 00'), with an uncertainty 
of 4.3 degrees (radius, 1-sigma containment, 
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees). 
The angle from the Fermi LAT boresight is 52 degrees.

The GBM light curve shows one major structured peak
with a duration (T90) of about 2.2 s (8-1000 keV). 
The time-averaged spectrum from T0-0.201 s to T0+1.655 s is 
best fit by a Band function with Epeak = 65 +/- 3 keV, 
alpha = 0.25 +/- 0.17, and beta = -2.80 +/- 0.15 
(chi squared 542 for 481 d.o.f.).
The event fluence (8-1000 keV) in this time interval is 
(1.64 +/- 0.28)E-06 erg/cm^2. The 1-sec photon flux measured 
starting from T0-0.073 s in the 8-1000 keV band 
is 11 +/- 3 ph/s/cm^2.

The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081105B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8495
SUBJECT: GRB 081105B: Fermi GBM detection
DATE:    08/11/07 17:01:51 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

Elisabetta Bissaldi (MPE) and A. von Kienlin (MPE) 
report on behalf of the Fermi GBM Team: 

"At 14:43:51.29 UT on 05 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081105B (trigger 247589032 / 081105614).
The on-ground calculated location, using the GBM trigger 
data, is RA = 215.7 deg, Dec = 42.8 (J2000 degrees, 
equivalent to 14h 23m, 42d 48'), with an uncertainty 
of 12 degrees (radius, 1-sigma containment, 
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees). 
The angle from the Fermi LAT boresight is 87 degrees.

This short GRB consists of a single peak with an estimated
T90 (8-1000 keV) of 180 ms and T50 (8-1000 keV) of 64 ms.
The spectral fit to this weak event is poorly constrained.
A fit of the time-averaged spectrum from T0-0.067 s to T0-0.019 s  
by a simple power law function yields an index of -1.17 +/- 0.05 
(chi squared 311 for 421 d.o.f.).
The event fluence (8-1000 keV) in this time interval is 
(2.28 +/- 0.11)E-07 erg/cm^2. The photon flux on the 
16 ms timescale measured starting from T0-0.067 s 
in the 8-1000 keV band is 20 +/- 3 ph/s/cm^2. 

The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081102B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8496
SUBJECT: GRB 081102B: Fermi GBM detection
DATE:    08/11/07 17:26:42 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE) and E. Bissaldi (MPE) 
report on behalf of the Fermi GBM Team: 

"At 08:45:00.51 UT on 02 November 2008, the Fermi GBM triggered 
and located GRB 081102B (trigger 247308301/ 081102365). 
The on-ground calculated location, using the Fermi GBM trigger data, 
is RA = 231.2, Dec = 35.2  (J2000 degrees, equivalent to 
J2000 15h 25m, 35d 12'), with a statistical uncertainty of 6.1 degrees 
(radius, 1-sigma containment; there is additionally a systematic error 
which is currently estimated to be 2 to 3 degrees). 
The angle from the Fermi LAT boresight is 53 degrees.
 
The GBM light curve shows a double peak with a duration (T90) 
of about 2.2 s (8-1000 keV). The time-averaged spectrum from 
T0-0.226 s to T0+0.798 s (first peak) is well fit 
by a simple power law function with index -1.07 +/- 0.06 
(chi squared 247 for 243 d.o.f.). The event fluence (8-1000 keV) 
in the same time interval is (1.12 +/- 0.04)E-06 erg/cm^2. 
The 1-sec photon flux measured starting from T0-0.226 s in the 
8-1000 keV band is 3.68 +/- 0.14 ph/s/cm^2.

The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081024C
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8498
SUBJECT: GRB 081024C:  Fermi Gamma-ray Burst Monitor detection
DATE:    08/11/07 20:34:54 GMT
FROM:    Valerie Connaughton at MSFC  <valerie@nasa.gov>

Valerie Connaughton (UAH) reports on behalf of the Fermi GBM Team:

"At 20:25:34 UT on 24 October 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081024C (trigger 246572735 / 081024851).


The on-ground calculated location, using the GBM trigger
data, is RA = 147.6, DEC = -8.2 (J2000 degrees, equivalent to 09h50m,
 -08d12'), with an uncertainty of 3.2 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic error which is 
currently
estimated to be 2 to 3 degrees).  The angle from the Fermi LAT boresight
is 78 degrees.

The GBM light curve consists of a single weak peak with some
substructure, lasting about 65 seconds.
The time-averaged spectrum from T0-8 s to T0+57 s is best fit by
a Band function with Epeak = 65 +/- 7 keV,
alpha = -0.6 +/- 0.2, and beta = -2.5 +/- 0.2
(chi squared 358 for 355 d.o.f.)

The event fluence (50 -- 300 keV) in this time interval is
(4.0 +/- 0.9)E-6 erg/cm^2, and its 1-second peak flux in the same
energy range is approximately 1 ph/cm^2/sec.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081028A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8499
SUBJECT: GRB 081028 - PAIRITEL NIR detection
DATE:    08/11/08 23:10:09 GMT
FROM:    Adam Miller at UC Berkeley  <amiller@astro.berkeley.edu>

A. A. Miller, B. E. Cobb, J. S. Bloom, D. A. Perley (UC Berkeley), D. 
Starr (UCB, LCOGT) report:

We observed the optical afterglow of GRB 081028 (Clemens et al., GCN 
8424, Olofsson et al., GCN 8425) with the 1.3-m Peters Automated Infrared 
Imaging Telescope (PAIRITEL). Observations with PAIRITEL began at 11:26:23 
UT on Oct 28, 2008, 11 hours after the GRB trigger. We detect the 
afterglow in a 3727 sec mosaic of 7.8 sec simultaneous exposures in the 
J, H, and Ks filters. Preliminary photometry for the afterglow in these 
mosaics with midtime 12:13:59 Oct 28, 2008 UT yields J = 17.7 +- 0.1, H = 
17.0 +- 0.1, and  Ks = 16.1 +- 0.1 (all magnitudes given in the Vega 
system), calibrated to the 2MASS system. In intermediate mosiacs we find 
that the afterglow gets brighter during our ~1.5 hrs of observations. No 
correction for Galactic extinction (E(B-V) = 0.03; Schlegel et al. 1998) 
has been made to the above reported values.

These measurements indicate that the burst afterglow became 
brighter and redder following the measurements made by Clemens et al. 
(GCN 8424). Schady & Guidorzy (GCN 8431) report an optical brightening of 
the afterglow, consistent with the detected behavior in the NIR, around 
the time of our observations, and further measurements by Clemens et al. 
(GCN 8442) taken roughly 31 hours after the burst trigger show that the 
afterglow is redder than their initial observations.


GRB_name: GRB081109A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8500
SUBJECT: GRB 081109: Swift detection of a burst
DATE:    08/11/09 07:22:59 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

S. Immler (CRESST/GSFC/UMD), A. P. Beardmore (U Leicester),
J. R. Cummings (NASA/UMBC), P. A. Evans (U Leicester),
N. Gehrels (NASA/GSFC), S. D. Hunsberger (PSU),
K. L. Page (U Leicester), D. M. Palmer (LANL),
M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester),
T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the
Swift Team:

At 07:02:06 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081109 (trigger=334112).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 330.787, -54.719 which is 
   RA(J2000) = 22h 03m 09s
   Dec(J2000) = -54d 43' 06"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a triangular
structure with a duration of about 40 sec.  The peak count rate
was ~2500 counts/sec (15-350 keV), at 20 sec after the trigger. 

The XRT began observing the field at 07:03:12.2 UT, 65.6 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 330.7911, -54.7114 which is equivalent to:
   RA(J2000)  = 22h 03m 09.86s
   Dec(J2000) = -54d 42' 41.0"
with an uncertainty of 4.8 arcseconds (radius, 90% containment). This
location is 28 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

The initial flux in the 2.5 s image was 4.78e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 75 seconds after the BAT trigger. The 2.7'x2.7' sub-image covers 100%
of the XRT error circle. The typical 3-sigma upper limit has been about 19.6
mag. The 8'x8' region for the list of sources generated on-board covers 100% of
the XRT error circle. The list of sources is typically complete to about 18
mag. No correction has been made for the expected extinction corresponding to
E(B-V) of 0.02. No afterglow candidate has been detected. 

Burst Advocate for this burst is S. Immler (immler AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081109A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8501
SUBJECT: GRB 081109: REM NIR afterglow detection
DATE:    08/11/09 09:54:49 GMT
FROM:    Stefano Covino at Brera Astronomical Observatory  <stefano.covino@gmail.com>

P. D'Avanzo, S. Covino, L.A. Antonelli, D. Malesani, D. Fugazza, L.  
Calzoletti,  S. Campana, G. Chincarini, M.L. Conciatore, S. Cutini,  
V. D'Elia,  F. D'Alessio, F. Fiore, P. Goldoni, D. Guetta,  C.  
Guidorzi, G.L. Israel, E. Maiorano, N. Masetti, A. Melandri, E.J.A.  
Meurs, L. Nicastro, E. Palazzi, E. Pian, S. Piranomonte, L. Stella,  
G. Stratta, G. Tagliaferri, G. Tosti, V. Testa, S.D. Vergani, F.  
Vitali report on behalf of the REM team:

The robotic 60-cm REM telescope located at La Silla (Chile) observed  
automatically the field of the GRB 081109 (Immler et al. GCN 8500) on  
Nov 09 starting about 52 s after the burst.  Observations were  
carried out at high airmass (~ 6). We clearly detect an object in our  
first K-band image inside the XRT error box (Immler et al. GCN 8500)  
at the following coordinates (J2000):

R.A. = 22:03:09.72
Dec = -54:42:39.5

with an uncertainty of 1.0". The object is not visible in the single  
RJH images taken approximately at the same epoch. Coadding all the  
available RJH images taken around the same epoch we obtain the  
following results:

Mean_obs         texp   #frames_coadd    Filter    Mag

Nov 09.30604 UT  780 s     11   R    > 16.5 (3sigma)
Nov 09.30707 UT   65 s      4    J    > 15.8 (3sigma)
Nov 09.29936 UT   75 s      7    H    15.47  0.26
Nov 09.30145 UT   10 s      1    K    14.51  0.27

The object subsequently brightened, reaching K = 14.27  0.16 on Nov  
09.30612 UT. No object is detected at this position in the 2MASS and  
USNO catalogs. We propose this is the NIR afterglow of GRB 081109. We  
cannot indeed exclude the possibility that the lack of detection  
blueward of the H band is due to an high-redshift nature of this  
event. We note, however, that the large airmass badly affects the  
images in the J and R bands, so that our limits are not very  
constraining

Further deep optical/NIR observations are encouraged.


GRB_name: GRB081109A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8503
SUBJECT: GRB 081109A optical upper limit
DATE:    08/11/09 14:15:04 GMT
FROM:    AAVSO GRB Network at AAVSO  <matthewt@aavso.org>

Peter Nelson (Ellinbank, Victoria, Australia) reports to the AAVSO 
International High Energy Network the following optical observation of 
GRB081109A (GCN #8500 Immler et al.; GCN #8501 D'Avanzo et al.):

Peter Nelson has obtained a limiting magnitude on the optical afterglow of 
GRB081109A (Immler et al., GCN #8500).  The near IR afterglow position RA: 
22:03:09.72 Dec: -54:42:39.5 found by D'Avanzo et al. (GCN #8501) was observed 
for 120 seconds using a 0.32-meter Newtonian with an SBIG ST8XE 
CCD and an R filter under poor photometric conditions.  The mid-point of 
the observations was 2008 Nov 09.5188 UT, approximately 5.4 hours after the 
burst.  The afterglow was not detected to an upper limit of R=18.1, using 
the USNO-A2.0 star 0300-37476396 (R=13.2) as the comparison.

A detailed report of these observations is available on the AAVSO website 
at ftp://ftp.aavso.org/grb/PeterNelson_081109_2454780.06997_.txt

A fits image is available at
ftp://ftp.aavso.org/grb/PeterNelson_081109_2454780.06997_.fits

The AAVSO thanks the Curry Foundation for their continued support of the 
AAVSO International High Energy Network.


GRB_name: GRB081109A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8504
SUBJECT: GRB 081109: Swift/UVOT upper limits
DATE:    08/11/09 15:18:19 GMT
FROM:    Paul Kuin at MSSL  <npkuin@googlemail.com>

N. P. M. Kuin (MSSL/UCL) and S. Immler (CRESST/GSFC/UMD)
report on behalf of the Swift UVOT team.

The Swift UltraViolet/Optical Telescope (UVOT) began observing
GRB 081109 (Swift BAT trigger number 334112; Immler et al.,
GCN Circ. 8500) on November 9, 2008, with a white filter finding
chart at 07:03:23 UT, 75 seconds after the trigger.

No new source is detected in any of our images at the position
consistent with the reported XRT position in GCN Circ. 8500.

The magnitudes and upper limits for GRB081109 at this position
are given below:

Filter Tstart(s) Tstop(s)  Exp(s)  Magnitude

wh      75       6592     745      >21.49  (3-sigma UL)
u      287       6181     501      >20.57  (3-sigma UL)
b      543       6387     452      >20.35  (3-sigma UL)
uvw2   593       5362     274      >20.03  (3-sigma UL)
v      617       5566     274      >19.09  (3-sigma UL)
uvm2   641       5771     274      >19.87  (3-sigma UL)
uvw1   666       5976     255      >20.00  (3-sigma UL)

The values quoted above are on the UVOT Photometric System
(Poole et al, 2008, MNRAS 383, 627). They are not corrected for
the expected galactic reddening of E(B-V) = 0.019 in the direction
of the burst (Schlegel et al. 1998).


GRB_name: GRB081109A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8505
SUBJECT: GRB 081109: Fermi GBM detection
DATE:    08/11/09 15:56:47 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team: 

"At 07:02:02.42 UT on 09 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081109 (trigger 247906923 / 081109293), which was 
also detected by the SWIFT (S. Immler et al. 2008, GCN 8500).
The GBM on-ground location is consistent with the Swift position.

The GBM light curve shows a single peak
with a duration (T90) of about 45 s (8-1000 keV). 
The time-averaged spectrum from T0-6.144 s to T0+26.624 s is 
best fit by a power law function with an exponential
high energy cutoff.  The power law index is -1.28 +/- 0.09 and
the cutoff energy, parameterized as Epeak is 240 +/- 60 keV.
(chi squared 510 for 478 d.o.f.)
The event fluence (8-1000 keV) in this time interval is 
(6.53 +/- 0.43)E-06 erg/cm^2. The 1-sec photon flux measured 
starting from T0+9.216 s in the 8-1000 keV band 
is  3.2 +/- 0.3  ph/s/cm^2.

The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081109A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8506
SUBJECT: GRB 081109A: Swift-XRT refined analysis
DATE:    08/11/09 16:19:07 GMT
FROM:    Andy Beardmore at U Leicester  <apb@star.le.ac.uk>

A.P. Beardmore, K.L. Page (U. Leicester) and S. Immler (CRESST/GSFC/UMD) 
report on behalf of the Swift-XRT team.

The Swift-XRT started observing the field of GRB 081109A (trigger
#334112, Immler et al., GCN 8500) at 07:03:12.2 UT, 65.6 s after
the BAT trigger. The XRT observed the GRB in Windowed Timing (WT) mode 
until 318 s after the trigger and Photon Counting (PC) mode thereafter.

Using 4661 s of XRT Photon Counting mode data and 7 UVOT images, we
find an astrometrically corrected X-ray position (using the XRT-UVOT
alignment and matching to the USNO-B1 catalogue) of
RA, Dec = 330.7905, -54.7118 which is equivalent to :

RA  (J2000):  22h 03m 9.72s
Dec (J2000): -54d 42m 42.5s

with an uncertainty of 1.4 arcsec (90% confidence).  This is 2.98
arcsec from the reported possible NIR counterpart of D'Avanzo (GCN
8501).

The X-ray light curve from the first three orbits can be modelled with
a broken powerlaw with an initial decay slope of 1.78 +/- 0.06, a break 
time of 353 +/- 40 s, followed by a shallower decay slope of 0.99 +/- 0.04.

The spectrum of the WT data from orbit 1 (from T+71.9 s to T+318.4 s, 
where T is the trigger time) can be well fit by an absorbed powerlaw 
with a photon index of 1.72 +/- 0.08 and column density of 
(1.84 +/- 0.22) x 10^21 cm^-2, compared with the Galactic column 
density of 1.6 x 10^20 cm^-2 in the direction of the burst. The observed
0.3-10 keV flux is  (7.4 +/- 0.4) x 10^-10 erg cm^-2 s^-1. The 
corresponding unabsorbed 0.3-10 keV flux is (9.5 +/- 0.5) x 10^-10 
erg cm^-2 s^-1.

A powerlaw fit to a  spectrum  obtained from  PC mode data spanning 
orbits 2 to 3 (T+4.76 ks to T+12.88 ks) is best fit with a photon 
index of   2.20 +/- 0.20 and column density (3.1 +/- 0.7) x 10^21 cm^-2.
The observed 0.3-10 keV flux over this interval is (7.3 +/- 0.7) x 10^-12
erg cm^-2 s^-1. The  count-to-observed-flux conversion factor is 
6.0e-11 erg cm^-2 count^-1.

Assuming the X-ray emission from the burst continues to decline at the
same rate we predict an XRT count rate of 0.018 count s^-1 at T+24 hour, 
or an observed 0.3-10 keV X-ray flux of 1.1 x 10^-12 erg cm^-2 s^-1.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081109A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8507
SUBJECT: GRB 081109A, Swift-BAT refined analysis
DATE:    08/11/09 16:42:12 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

C. B. Markwardt (GSFC/UMD), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
S. Immler (CRESST/GSFC/UMD), H. A. Krimm (GSFC/USRA), D. M. Palmer (LANL),
T. Sakamoto (GSFC/UMBC), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+962 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 081109A (trigger #334112)
(Immler, et al., GCN Circ. 8500).  The BAT ground-calculated position is
RA, Dec = 330.798, -54.711 deg, which is 
   RA(J2000)  =  22h 03m 11.5s 
   Dec(J2000) = -54d 42' 40.5" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 73%.
 
The mask-weighted light curve shows a smooth rise to a single peak
starting at ~T-90 sec, peaking at ~T+5 sec, and roughly exponentially decaying
back to baseline at ~T+400 sec.
T90 (15-350 keV) is 190 +- 60 sec (estimated error including systematics).
 
The time-averaged spectrum from T-15.9 to T+416.1 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.72 +- 0.09.  The fluence in the 15-150 keV band is 3.6 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+7.64 sec in the 15-150 keV band
is 1.1 +- 0.0 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/334112/BA/


GRB_name: GRB081109A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8508
SUBJECT: GRB 081109A: Faulkes Telescope South observations
DATE:    08/11/09 19:27:53 GMT
FROM:    David Bersier at Liverpool John Moores U  <dfb@astro.livjm.ac.uk>

C. Guidorzi (INAF-OAB), D. Bersier, M. Burgdorf, C.G. Mundell (LJMU)
and N. Tanvir (U. Leicester) report on behalf of a larger collaboration:

We observed GRB 081109A (Immler et al. GCN Circ. 8500) with the 2m
Faulkes Telescope South starting on November 11 at 11:50:36 UT
(corresponding to 4.81 hours post burst) in the R and i' filters.
We do not detect any object at the position of the REM afterglow
(D'Avanzo et al., GCN Circ 8501) down to magnitudes 21.0 and 21.2
in the R and i' filters respectively.

These upper limits are conservative however, as there is a possible
flux excess at the position of the REM afterglow but further analysis
is required to ascertain the reality of this source.

The calibration was performed using the R2 and I values of the
nearby USNOB1 star RA=22:03:01.679, Dec=-54:43:07.05 (R2=16.88, I=16.46).


GRB_name: GRB081109A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8509
SUBJECT: GRB 081109A: Possible Swift-UVOT detection
DATE:    08/11/10 01:35:23 GMT
FROM:    Stefan Immler at NASA/GSFC  <stefan.m.immler@nasa.gov>

S. Immler (CRESST/UMD/GSFC), N. P. M. Kuin (MSSL/UCL), and S. T. Holland 
(CRESST/USRA/GSFC) report on behalf of the Swift UVOT team:

Further analysis of Swift Ultraviolet/Optical Telescope (UVOT) data of 
GRB 081109A (Immler et al., GCN Circ. 8500), starting 75 sec after the 
BAT trigger, gives a tentative detection of an optical source at the 
reported REM position (D'Avanzo et al., GCN Circ 8501) in the white 
filter at a 3.3-sigma level of confidence. The source is not detected in 
any of the other UVOT filters at the limiting magnitudes reported below.

Filter Tstart(s) Tstop(s)  Exp(s)  Magnitude

wh      75       6592     745      21.6+/-0.3
u      287       6181     501      >21.5  (3-sigma UL)
b      543       6387     452      >20.9  (3-sigma UL)
uvw2   593       5362     274      >21.6  (3-sigma UL)
v      617       5566     274      >20.9  (3-sigma UL)
uvm2   641       5771     274      >21.5  (3-sigma UL)
uvw1   666       5976     255      >21.5  (3-sigma UL)

The possible detection in the white filter, combined with the lack of a 
detection in the v filter, is consistent with the source having a 
redshift greater than 5.5.

Follow-up observations, especially in the infrared, are encouraged.


GRB_name: GRB081109A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8510
SUBJECT: GRB 081109: GROND Detection of the Optical/NIR Afterglow Candidate
DATE:    08/11/10 03:34:52 GMT
FROM:    Christian Clemens at MPE  <cclemens@mpe.mpg.de>

C. Clemens, T. Kruehler, J. Greiner (all MPE Garching) and G. Szokoly 
(Eoetvoes Univ., Budapest and MPE) report on behalf of the GROND team:

We observed the field of GRB 081109 (Swift trigger #334112; Immler et al., GCN 
#8500) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 
120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla Observatory 
(Chile).
 
Observations started at 00:08 UT on November 10th, 2008, 17.1 hr after the GRB 
trigger, and are continuing. They were performed during astronomical twilight 
at an average seeing of 1.0" and at an average airmass of 1.1 as well as 
under bright Moon.
 
Based on the first 7.7 min of total exposures in g'r'i'z' and 8.0 min in JHK, 
we detect the afterglow candidate reported by D'Avanzo et al. (GCN #8501) and 
estimate preliminary magnitudes (all in AB system) of
 
g' > 22.8
r' ~ 22.8 +/- 0.3
i' ~ 21.8 +/- 0.15
z' ~ 21.4 +/- 0.15
J ~ 20.4 +/- 0.10
H ~ 19.7 +/- 0.15
K ~ 18.9 +/- 0.20
 
These magnitudes are calibrated against GROND zeropoints as well as 
2MASS field stars.
 
The spectral energy distribution is very red, and requires an extinction
of A_V > 0.5. With this strong extinction, and our g'-band limit being
compromised by the nearby full Moon, we cannot derive a redshift
at this stage.


GRB_name: GRB081109B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8511
SUBJECT: GRB 081109B: Swift/UVOT refined analysis
DATE:    08/11/10 11:20:01 GMT
FROM:    Paul Kuin at MSSL  <npkuin@googlemail.com>

N. P. M. Kuin (MSSL/UCL) and S. Immler (CRESST/GSFC/UMD) report on behalf
of the Swift UVOT team.

The Swift UltraViolet/Optical Telescope (UVOT) began observing GRB 081109B
(Swift BAT trigger number 334129; Immler et al., GCN Circ. 8502) on
November 9, 2008, at 13:50:24 UT, 187 seconds after the trigger.

No new source is detected in any of our images or summed images which
cover the BAT error circle descibed in GCN Circ. 8502.

The 5-sigma upper limits in the summed images for GRB081109B at a random
background position within the BAT error circle are given below:

Filter Tstart(s) Tstop(s)  Exp(s)  Magnitude

wh     187       5946     560      >20.78 (5-sigma UL)
u      393      12195     533      >20.1  (5-sigma UL)
b      418       5741     235      >19.9  (5-sigma UL)
uvw2   468       6152     413      >19.8  (5-sigma UL)
v      492       6357     413      >19.3  (5-sigma UL)
uvm2   344      10975    1142      >20.2  (5-sigma UL)
uvw1   369      11882    1121      >20.5  (5-sigma UL)

The values quoted above are on the UVOT Photometric System (Poole et al,
2008, MNRAS 383, 627). They are not corrected for the expected galactic
reddening of E(B-V) = 0.01 in the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB081109B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8512
SUBJECT: Swift-BAT refined analysis of trigger 334129
DATE:    08/11/10 13:39:49 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC),
S. Immler (CRESST/GSFC/UMD)
(on behalf of the Swift-BAT team):

Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT possible burst GRB 081109B (trigger #334129)
(Immler, et al., GCN Circ. 8502).  Given the extremely weak recorded flux,
the lack of an XRT detection (private communication), and the specrtal softness,
this trigger is very likely not due to a GRB.  However, we can not completely
rule out a GRB orgin.  If it were due to a GRB, then the following would apply:

The BAT ground-calculated position is RA, Dec = 350.132, -55.912 deg,
which is 
   RA(J2000)  =  23h 20m 31.8s 
   Dec(J2000) = -55d 54' 42.8" 
with an uncertainty of 3.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 96%.
 
The mask-weighted light curve shows a weak peak starting at ~T+15 sec
and ending at ~T+115 sec.
 
The time-averaged spectrum from T+0.0 to T+128.0 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.21 +- 0.56.  The fluence in the 15-150 keV band is 2.3 +- 0.9 x 10^-7 erg/cm2.
All the quoted errors are at the 90% confidence level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/334129/BA/


GRB_name: GRB081024B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8513
SUBJECT: GRB 081024B: Swift-XRT late-time observations
DATE:    08/11/10 16:01:33 GMT
FROM:    Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>

C. Guidorzi (INAF-OAB) on behalf of the Swift-XRT team reports:

Swift-XRT re-observed the field of the Fermi-LAT and Fermi-GBM
GRB 081024B (Omodei et al. GCN Circ. 8407; Connaughton et al GCN Circ. 8408)
from 13.1 to 15.1 days after the burst with a net exposure of 9.8 ks.

We compared this with our previous observations (Guidorzi et al. GCN Circ.
8410, 8416, 8454). We still detect source 2, identified in our first
observation (Guidorzi et al. GCN Circ. 8410), with a count rate of
(1.1 +- 0.4)e-3 count/s, which is compatible with a constant rate
source throughout the entire XRT observations.
We also derived an upper limit to the possible power-law decay
index of alpha<0.4 from ~1e5 to ~1.3e6 s (90% confidence).
We conclude that source 2, initially proposed as possibly associated
with GRB 081024B (Guidorzi et al. GCN Circ. 8416, 8454), is not the
corresponding X-ray afterglow.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081025A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8514
SUBJECT: GRB 081025: Swift-XRT further analysis
DATE:    08/11/10 17:05:33 GMT
FROM:    Jirong Mao at INAF-OAB  <jirong.mao@brera.inaf.it>

J. Mao (INAF-OAB) on behalf of the Swift-XRT team reports:

Swift-XRT re-observed the Swift-BATSS GRB 081025 (Copete et al., GCN 
8409) from 12.9 days after the burst with an exposure time of 6.9 ks.

We did not detect any source in the field. The 3-sigma upper limit is 
1.7e-3 count/s. We compared this result with the previous observation 
(Mao et al., GCN 8411). Thus we confirm that XRT observed the fading 
afterglow of GRB 081025. 

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081109A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8515
SUBJECT: GRB 081109: GROND redshift limit and host extinction
DATE:    08/11/10 19:25:43 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

C. Clemens, T. Kruehler, J. Greiner (all MPE Garching) report on
behalf of the GROND team:

We report on further analysis of the GROND data of GRB 081109 detected
by Swift (trigger 334112; Immler et al., GCN #8500) and Fermi/GBM
(von Kienlin 2008, GCN #8505) taken simultaneously in g'r'i'z'JHK.

In a combined 2~h exposure at a midtime of 18.5~hours after the burst, 
we clearly detect the afterglow reported by D'Avanzo et al. (GCN 
#8501) and Clemens et al. (GCN #8510) in all filters.

Using 2MASS field stars in JHK and the GROND zeropoints in g'r'i'z' we 
estimate preliminary AB magnitudes of

g' = 23.14 +- 0.18 mag,
r' = 22.55 +- 0.15 mag,
i' = 22.00 +- 0.16 mag,
z' = 21.54 +- 0.15 mag,
J  = 20.49 +- 0.07 mag,
H  = 19.56 +- 0.06 mag and
K  = 18.84 +- 0.10 mag

which have been corrected for the expected Galactic reddening of 
E_(B-V)=0.02 (Schlegel et al. 1998).

Assuming Ly-alpha absorption, the g' band detection implies a redshift 
of z < 3.5.

The Galactic foreground corrected broad band SED is best fit with a 
power law template and significant extinction in the host. Depending 
on the used model, the  best fit intrinsic extinction A_V^{host} 
varies between 0.6 and 1.2. We caution however, that this is strongly 
dependent on the unknown redshift and subject to changes due to an
future improved calibration.


GRB_name: GRB081102A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8516
SUBJECT: GRB 081102: MASTER refind and final results  
DATE:    08/11/11 15:50:10 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

E. Gorbovskoy, V. Lipunov, V.Kornilov, 
A.Belinski, N.Shatskiy, N.Tyurina, D.Kuvshinov, P.Balanutsa
Sternberg Astronomical Institute, Moscow State University

A. Tlatov, A.Parkhomenko
Kislovodsk Solar Station of the Pulkovo Observatory

V.Krushinski, I.Zalognikh
Ural State University, Kourovka


S.Yazev, K.Ivanov
Irkutsk State University


Two of the four  MASTER Very Wide Field Cameras located at Kislovodsk
(http://apollo.sai.msu.ru/, D=50 mm, 4x1000 square degrees, 35'' per pix) has 
observed the Swift-BAT GRB081102 error box  (Mangano et al., GCN Circ 
8470, Lipunov et al., GCN 8464, 8471) 
with 5s exposures during all night without time gap between images. There 
are  two  separeted (~702m) mount with double cameras.

Now we present results from the North and South mounts.

These unfiltered images are calibrated relative to Tycho stars (V).
We do not detect any new source at the XRT position
reported in GCN Circ. 8470 (Mangano et al.) brighter than 13.0 
mag before and after trigger time.
The photometry results +-4 min around trigger time:


  T-T_trigger            m_lim (S/N=3)         Exposure         Coadd

-255s... 0... 255 s       11.8                  5s              yes 
-2min...0...+2 min        12.7                 2x30s             12
-2min...0...+2 min        13.0                 2x60s             24

The optical fluence during the 40s-GRBurst is limited by

     <= 1.6x10_-8 erg/cm_2


including 2.8 magnitude  absorbtion (Ukwatta et al., Circ 8462).
The  BAT-fluence is aboute 2.3x10_-6 erg/cm_2 (15-150 keV) 
(Fenimore et al., GCN 8468).

So:

Optical Fluence/Gamma-Fluence(15-150keV) ~ < 1/140

Same ratio for GRB080319B is ~ 1/25 (Naked Eye GRB) in 15-150 keV 
(Racusin, Karpov et al., Nature, vol.455, 183, 2008).


Scientific Master Team Report   are available at
http://observ.pereplet.ru/images/GRB081102/grb_film.html

Note: the GRB was at the edge of the FOW in both cameras.
The message may be cited.

mailto: lipunov@sai.msu.ru


GRB_name: GRB081109A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8517
SUBJECT: GRB 081109: TAROT La Silla observatory optical observations
DATE:    08/11/12 09:21:09 GMT
FROM:    Alain Klotz at CESR-CNRS  <Alain.Klotz@free.fr>

Klotz, A. (CESR-OMP), Gendre B. (LAM-OAMP),
Boer M. (OHP-OAMP), Atteia J.L. (LATT-OMP) report:

We imaged the field of GRB 081109 detected by SWIFT
(trigger 334112) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 29.4s after the GRB trigger.
The elevation of the field decreased from
11 degrees above horizon and weather conditions
were excellents.

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect the afterglow mentioned by D'Avanzo et
al. (GCNC 8501) with a limiting magnitude of:

t0+29.4s to t0+89.4s : R > 16.9

This image was taken during the gamma emission.
This means that there was no bright optical flash
associated to this burst.

The second image is 30.0s exposure in tracking mode.
We detect the afterglow:

t0+95.1s to t0+125.1s : R ~ 17.8 +/- 0.2

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.

This message may be cited.


GRB_name: GRB081110A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8518
SUBJECT: GRB 081110: MASTER: first optical observations Fermi GRB
DATE:    08/11/13 14:23:06 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

D.Kuvshinov,, E. Gorbovskoy, V.Lipunov, V.Kornilov, A.Belinski, 
N.Shatskiy, N.Tyurina, D.Kuvshinov, P.Balanutsa
Sternberg Astronomical Institute, Moscow State University

A. Tlatov, A.Parkhomenko
Kislovodsk Solar Station of the Pulkovo Observatory

V.Krushinski, I.Zalognikh
Ural State University, Kourovka


S.Yazev, K.Ivanov
Irkutsk State University


Sternberg Astronomical Institute, Moscow Union 'Optic'

MASTER-Moscow  robotic telesope
(http://observ.pereplet.ru, D=355 mm, FOW=2.4x2.4 square degrees) observed
GRB  trigger number  248019944  error box (GRB_TIME is   14:25:43.03UT 
10 Nov 2008, 
http://gcn.gsfc.nasa.gov/fermi_grbs.html, error box=2.7x2.7 degrees) in 
survey mode after error box rise (but under full Moon).

The coordinates of the error box center:

R.A. = 07h 18m 14s
Dec =  +17d 19' 12"

The first image was at 2008-11-10 21:07:58.2 UT,
6 hours 42 min   after the GRB time. The last image was at 2006-04-26
23:13:31.00 UT, 8  hours 48  min   after the GRB time.
We have 89 images with limit for coadded one up to 19m (S/N = 4).

The unfiltered image is calibrated relative to USNO B1.0 (0.8 R + 0.2 B).


This message can be cited.
Mailto: lipunov@sai.msu.ru


GRB_name: GRB081110A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8519
SUBJECT: GRB 081110: Fermi GBM detection
DATE:    08/11/13 18:30:28 GMT
FROM:    Sheila McBreen at MPE  <smcbreen@mpe.mpg.de>

Sheila McBreen (UCD/MPE) and Elisabetta Bissaldi (MPE)
report on behalf of the Fermi GBM Team:

"At 14:25:43.03 UT on 10 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081110 (trigger 248019944 / 081110601).
The on-ground calculated location, using the GBM trigger
data, is RA = 123.6, DEC = +21.2 (J2000 degrees,
equivalent to 08h 14 m, 21 d 12'), with an uncertainty
of 1 degree (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
The angle from the Fermi LAT boresight is 67 degrees.

The burst has a duration (T90) of about 20 s (8-1000 keV).
The GBM light curve consists of three pulses, a bright
FRED-like pulse from T0 to T0+5 s, a second weaker
pulse at T0+9 s followed by weaker emission out to about T0+20 s.
This is a hard gamma-ray burst with events detected up
to about 2 MeV. Spectral analysis is on-going.

The final results will be published in the GBM GRB Catalog."


GRB_name: GRB081102A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8520
SUBJECT: GRB 081102: RTT150 Optical observations
DATE:    08/11/13 18:30:53 GMT
FROM:    Irek Khamitov at TUG  <irekk@tug.tug.tubitak.gov.tr>

I. Khamitov, M.Parmaksizoglu (TUG), S.Alis, M.Hudaverdi (Istambul Uni.),
Z. Eker (TUG), U. Kiziloglu (METU),  E. Gogus (Sabanci Uni.),
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),
I. Bikmaev, N. Sakhibullin (KSU/AST)

report:

We observed the field of the Swift-BAT GRB 081102 (Ukwatta et al., 
GCN8462) with Russian-Turkish 1.5-m  telescope (RTT150, Bakirlitepe, 
TUBITAK National Observatory, Turkey), starting at 03 Nov, 17:44 UT, i.e. 
approximately 24.0 hours after the burst, using TFOSC CCD.

We made 3x300s exposures in R-band. We do not detect any new source inside
the XRT error circle (Osborne et al., GCN8467). Using USNO-B1 stars we 
estimated the limiting magnitude of combined image as m_R ~ 22.



-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.


GRB_name: GRB081113A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8521
SUBJECT: GRB 081113: Fermi GBM detection
DATE:    08/11/14 16:00:58 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team: 

"At 05:31:32.90 UT on 13 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081113 (trigger 248247093 / 081113230). 
The on-ground calculated location, using the GBM trigger 
data, is RA = 146.7, DEC = +68.9 (J2000 degrees,  
equivalent to 09h 47m, 68d 54'), with an uncertainty    
of 9.1 degrees (radius, 1-sigma containment, 
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees). 
The angle from the Fermi LAT boresight is 60.0 degrees.
This burst was also independently detected by INTEGRAL SPI-ACS.

This GRB with an estimated T90 (8-1000 keV) of 0.5 s
consists of two short peaks (of ~250 ms and ~150 ms sec 
duration, resp.). The time-averaged spectrum from T0-0.080 s 
to T0+0.432 s is well fit by a simple power law function 
with index -1.28 +/- 0.05 (chi squared 246 for 241 d.o.f.).
The event fluence (8-1000 keV) in this time interval is 
(1.07 +/- 0.03)E-06 erg/cm^2. The photon flux on the 
64 ms timescale measured starting from T0-0.016 s 
in the 8-1000 keV band is 20 +/- 1 ph/s/cm^2. 

The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081105A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8522
SUBJECT: Further Swift-XRT observations of the probable GRB 081105.
DATE:    08/11/16 01:15:46 GMT
FROM:    Andy Beardmore at U Leicester  <apb@star.le.ac.uk>

A.P. Beardmore (U. Leicester), D.N. Burrows (PSU), J.R. Cummings (NASA/UMBC) 
report on behalf of the Swift-XRT team.

The Swift-XRT reobserved the field of the Swift-BAT and IPN localisation 
GRB 081105 (Cummings et al., GCN 8484) for a further 9.8 ks starting at 
2008-11-12T04:15:51(UT), 6.62 days after the trigger.

Using a 10 pixel radius extraction region we detect 9 counts at the 
position of the XRT source reported in GCN 8487 (Beardmore & Cummings) 
compared with 1.28+/-0.20 estimated background counts. The Bayesian method 
of Kraft et al. (1991 ApJ 374 344) produces a 3 sigma confidence level on 
the expected source counts of S_min = 1.40 to S_max = 20.08, suggesting 
the source is detected. (The lower limit on the expected source counts, 
S_min, approaches zero when the confidence level reaches 4.4 sigma.) The 
estimated source count rate is (1.07+/-0.40)e-3 count/s (where the quoted 
error is 1 sigma), compared with a value of 0.0065 +/-0.0015 count/s from 
the earlier observation.

By fitting the low counts per bin data using Cash statistics, we find
the source has faded with a decay slope of 1.01 +0.38-0.32. Both the
source intensity and decay is comparable to those seen in other long GRBs 
at this stage of their outburst (e.g. see 
http://www.swift.ac.uk/xrt_curves/allcurves.php).

We suggest the X-ray source reported in GCN 8487 was the counterpart to 
the BAT/IPN localisation and its decaying nature gives further weight to a 
GRB interpretation.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081109A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8523
SUBJECT: GRB 081109A: confirmation of possible detection host galaxy
DATE:    08/11/17 00:02:24 GMT
FROM:    Paul Kuin at MSSL  <npkuin@googlemail.com>

N. P. M. Kuin (MSSL/UCL) and  S. Immler(CRESST/GSFC/UMD) report on
behalf of the Swift UVOT team.

Continued observations by the Swift UltraViolet/Optical Telescope
(UVOT) of the field of GRB 081109A  (Immler et al., GCN Circ. 8500,
Kuin and Immler, GCN Circ. 8504, Immler et al., GCN Circ. 8509)
confirm that a weak source is present close to the REM position
(D'Avanzo et al, GCN Circ. 8501) and also close to the refined
XRT position (Beardmore et al., GCN Circ. 8506).

We detect a constant source in 166 images totaling 54.4 ks of exposure time
over a period of 544 ks (~1 week) in the UVOT white filter at position:

RA = 22:03:09.579, Dec = -54.42.40.49 (J2000)

with an uncertainty of 0.8 arcsec (90% confidence). The source
magnitude in the summed image is wh = 22.86 +/- 0.09 mag (11.5 sigma detection).

The values quoted above are on the UVOT Photometric System
(Poole et al, 2008, MNRAS 383,627). They are not corrected for the
expected galactic reddening of E(B-V) = 0.019 in the direction of
the burst (Schlegel et al. 1998).

We interpret this image as the possible host galaxy. In that case the
REM position offset suggests that the GRB took place on the edge of the
host galaxy. The source we detect is also just outside the XRT error
circle.


GRB_name: GRB081118A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8524
SUBJECT: GRB 081118: Swift detection of a burst
DATE:    08/11/18 15:10:34 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

E. A. Hoversten (PSU), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
M. Capalbi (ASDC), P.A. Curran (MSSL-UCL), M. De Pasquale (UCL-MSSL),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
O. Godet (U Leicester), D. Grupe (PSU), C. Guidorzi (INAF-OAB),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
V. Mangano (INAF-IASFPA), J. Mao (INAF-OAB),
J. P. Osborne (U Leicester), C. Pagani (PSU), D. M. Palmer (LANL),
J. L. Racusin (PSU), P. Romano (INAF-IASFPA),
B. Sbarufatti (INAF-IASFPA), P. Schady (MSSL-UCL),
R. L. C. Starling (U Leicester), G. Tagliaferri (INAF-OAB),
E. Troja (INAF-IASFPA), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU)
report on behalf of the Swift Team:

At 14:56:36 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081118 (trigger=334877).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 82.590, -43.302 which is 
   RA(J2000)  =  05h 30m 22s
   Dec(J2000) = -43d 18' 07"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  Even though this is an image trigger,
there appears to be a peak of about 600 counts/sec starting 20 to 40 sec
after the start of the trigger integration. 

The XRT began observing the field at 14:59:10.0 UT, 153.3 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 82.59254, -43.30058 which
is equivalent to:
   RA(J2000)  = 05h 30m 22.21s
   Dec(J2000) = -43d 18' 02.1"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 8.4 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
3.74e+20 cm^-2 (Kalberla et al. 2005). 

The initial flux in the 2.5 s image was 6.01e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 164 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.04. 

Burst Advocate for this burst is E. A. Hoversten (hoversten AT astro.psu.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081118A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8525
SUBJECT: GRB 081118: Enhanced Swift-XRT position
DATE:    08/11/18 22:42:58 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 4848 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 081118, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 82.5928, -43.3009 which is equivalent
to:

RA (J2000): 05h 30m 22.28s
Dec (J2000): -43d 18' 03.1"

with an uncertainty of 2.0 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081118A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8526
SUBJECT: GRB 081118: Swift-BAT refined analysis
DATE:    08/11/19 00:07:42 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
E. A. Hoversten (PSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 081118 (trigger #334877)
(Hoversten, et al., GCN Circ. 8524).  The BAT ground-calculated position is
RA, Dec = 82.572, -43.305 deg, which is 
   RA(J2000)  =  05h 30m 17.3s 
   Dec(J2000) = -43d 18' 16.2" 
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 61%.
 
The mask-weighted light curve shows a roughly symmetrical peak starting
at ~T+10 sec, peaking at ~T+25 sec, and ending at ~T+105 sec.
T90 (15-350 keV) is 67+- 28 sec (estimated error including systematics).
 
The time-averaged spectrum from T+19.6 to T+118.6 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.10 +- 0.16.  The fluence in the 15-150 keV band is 1.2 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+46.97 sec in the 15-150 keV band
is 0.6 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/334877/BA/


GRB_name: GRB081118A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8527
SUBJECT: GRB 081118: Swift UVOT Upper Limits
DATE:    08/11/19 01:10:01 GMT
FROM:    Erik Hoversten at Swift/Penn State  <hoversten@astro.psu.edu>

E. A. Hoversten (PSU) reports on behalf of the Swift UVOT team:

The Swift/UVOT began settled observations of the field of
GRB 081118 150s after the BAT trigger (Hoversten et al., GCN 8524).
We do not detect any source at the enhanced Swift XRT position (Evans
et al., GCN 8525).  UVOT magnitude 3-sigma upper limits are reported
in the following table:

Filter   T_start   T_stop   Exp(s)  Mag (3-sigma upper limit)
-------------------------------------------------------------
white       150      300     147      > 21.32
white       854     1004     147      > 21.29
white      5726     5926     196      > 21.50
v          6137     6337     196      > 19.79
b          5522     5721     196      > 20.82
u          5316     5515     196      > 20.49
uvw1       5111     5310     196      > 20.26
uvm2       4905     5105     196      > 19.88
uvw2       5933     6132     196      > 20.24

The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight of E_(B-V) = 0.04 mag.
All photometry is on the UVOT photometric system described in Poole et
al. (2008, MNRAS, 383, 627).


GRB_name: GRB081118A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8528
SUBJECT: GRB 081118: optical afterglow candidate
DATE:    08/11/19 01:49:12 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo (INAF-OAB), V. D'Elia (INAF-OAR), S. Covino (INAF-OAB), S. 
Piranomonte (INAF-OAR), R. Salvaterra (INAF-OAB), C. C. Thoene (INAF-OAB), 
G. Chincarini (Un. Bicocca) report on behalf of the MISTICI collaboration:

We observed the field of GRB 081118 (Hoversten et al. GCN 8524) with the 
ESO-VLT equipped with the FORS2 camera on Nov 19.0431 UT (about 10 hours 
after the burst). We detect an object in our R-band images at the edge 
of the refined XRT error box (Evans et al. GCN 8525). The object is 
around R ~ 22.5. At present it is not possible to say if it is variable 
or not. Object coordinates are (J2000):

R.A. = 05:30:22.18
Dec = -43:18:05.3

+/- 0.5". Further analysis is ongoing.

We acknowledge support from the ESO staff, in particular Antonio de 
Ugarte Postigo.

[GCN OPS NOTE(19nov08): Per author's request, "C. Thone" was changed
to "C. C. Thoene".]


GRB_name: GRB081118A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8529
SUBJECT: GRB 081118: GROND detection of afterglow
DATE:    08/11/19 03:58:56 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

S. Loew, J. Greiner, A. Yoldas (all MPE Garching), A. Kuepcue Yoldas (ESO), 
G. Szokoly (Eoetvoes Univ., Budapest, and MPE) report for the GROND team:

We observed the field of GRB 081118 (Swift trigger 334877; Hoversten et al., 
GCN #8524) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, 
PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla Observatory
(Chile). Observations started at 00:35 UT on November 19th, 2008, 9.6 hr 
post-burst, when the GRB location was becoming visible at 20 degrees above 
horizon. Observations were performed at an average seeing of 1.0".

We detect the source reported by D'Avanzo et al. (GCN #8528) at the edge of 
the astrometrically corrected 2.0'' Swift-XRT error circle (Evans et al., 
GCN #8525). Based on a 20 min exposure at mid-time 1:55 UT, we estimate 
preliminary magnitudes (all in AB system) of

g' ~ 23.3 mag,     
r' ~ 23.0 mag,     
i' ~ 22.5 mag,     
z' ~ 22.0 mag,
J  ~ 21.6 mag,     
H  ~ 21.2 mag and  
K  ~ 20.6 mag      

with errors of +/- 0.2. These magnitudes are calibrated against GROND
zeropoints as well as 2MASS field stars, and are not corrected for the
galactic foreground extinction of E(B-V)= 0.04 (Schlegel et al. 1998).

The object clearly decayed by 0.6 mag over the course of 1.5 hrs, thus it 
is suggested as the couterpart of GRB 081118.

The spectral energy distribution is consistent with a power law, so the 
g'-band detection implies a redshift of this GRB smaller than 3.5.


GRB_name: GRB081118A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8530
SUBJECT: GRB 081118: Swift-XRT refined analysis
DATE:    08/11/19 04:09:56 GMT
FROM:    Loredana Vetere at PSU  <vetere@astro.psu.edu>

L. Vetere, E. Hoversten (PSU) report on behalf of the Swift-XRT team.

The Swift-XRT started observing the field of GRB 081118 (trigger=334877,
Hoversten et al., GCN 8525) at 14:59:10.0 UT, 153.3 s after the BAT  
trigger.
The XRT observed the GRB in Windowed Timing (WT) mode until 216 s
after the trigger and Photon Counting (PC) mode thereafter.

The X-ray light curve from the first three orbits can be modelled with  
a broken
powerlaw with an initial rapid decay (slope of 4.8+/-1.0), a break  
time of 580 s,
followed by a shallower decay (slope of 0.6+/-0.3).

The spectrum of the WT data can be well fit by an absorbed powerlaw  
with a
photon index of 2.6 +/- 0.3 and an absorbing equivalent hydrogen column
density consistent with the Galactic one in the GRB direction (3.7e20  
cm^-2;
Kalberla et al.  2005). The observed (unabsorbed) 0.3-10 keV flux is  
1.79
(2.28) x 10^-10 erg cm^-2 s^-1.

The PC spectrum (T+250 s to T+19 ks) is best fit with a photon index of
2.5 +/- 0.3 and an absorbing equivalent hydrogen column density  
consistent
  with the Galactic one in the GRB direction (3.7e20 cm^-2; Kalberla  
et al.  2005).
The observed (unabsorbed) 0.3-10 keV flux over this interval is 7.6  
(9.4) x
10^-13 erg cm^-2 s^-1.

Assuming the X-ray emission from the burst continues to decline at the
same rate we predict an XRT count rate of 0.002 count s^-1 at T+24 hour,
or an observed 0.3-10 keV X-ray flux of 5.2 x 10^-14 erg cm^-2 s^-1.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081118A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8531
SUBJECT: GRB 081118: VLT redshift
DATE:    08/11/19 05:42:21 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

V. D'Elia (INAF-OAR),  C. C. Thoene (INAF-OAB), A. De Ugarte Postigo 
(ESO), P. D'Avanzo, S. Covino (INAF-OAB), S. Piranomonte (INAF-OAR), R. 
Salvaterra (INAF-OAB), G. Chincarini (Univ. Bicocca) report on behalf of 
the MISTICI collaboration:

We observed the optical afterglow candidate of GRB 081118 (D'Avanzo et 
al. GCN 8528; Loew et al. GCN 8529) with the ESO-VLT equipped with the 
FORS2 camera starting on Nov 19.1166 (about 12 hours after the burst) in 
spectroscopic mode. We took 2x30 min spectra covering the range 
4300-9000 Angstrom (based on a preliminary wavelength calibration) with 
a resolution of R=440.

We detect a broad absorption feature around lambda_obs = 4350 Angstrom. 
Interpreting this feature as Ly-alpha absorption the inferred redshift 
is z = 2.58. At this redshift we also detect the SiII (1260), SiII 
(1304), CII (1334), SiIV (1393,1402) doublet, SiII (1526), CIV 
(1548,1550) doublet, FeII (1608), AlII (1670), SiII (1808) and AlIII 
(1854).

We acknowledge support from the ESO staff.


GRB_name: GRB081118A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8532
SUBJECT: VLA Radio upper limit on GRB 081118
DATE:    08/11/20 16:23:56 GMT
FROM:    Poonam Chandra at U Virginia/NRAO  <pc8s@virginia.edu>

Poonam Chandra (RMC) and Dale A. Frail (NRAO) report on
behalf of the Caltech-NRAO-Carnegie GRB Collaboration:

"We used the Very Large Array to observe the field of view toward
optically bright GRB 08118 (GCN 8524) at a frequency of 8.46 GHz
on 2008 Nov 20.35 UT. The GRB radio afterglow is undetected and
the peak radio flux at the ESO-VLT optical afterglow position 
(GCN 8528) is -70  60 uJy.

The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."


GRB_name: GRB081119A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8533
SUBJECT: GRB 081119: Fermi GBM detection
DATE:    08/11/20 18:15:16 GMT
FROM:    Sheila McBreen at MPE  <smcbreen@mpe.mpg.de>

Sheila McBreen (UCD/MPE) reports on behalf of the
Fermi GBM Team:

"At 04:25:27.06 UT on 19 November 2008, the Fermi Gamma-Ray Burst  Monitor
triggered and located a weak, short burst GRB 081119
(trigger 248761528 / 081119184).

The on-ground calculated location, using the GBM trigger
data, is RA = 341.4, DEC = 29.7 (J2000 degrees,
equivalent to 22h 46 m, 29 d 42'), with an uncertainty
of 15 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
The angle from the Fermi LAT boresight is 86 degrees.

The GBM light curve consists of one pulse
with a duration (T90) of about 0.8 s (8-1000 keV).
The time-averaged spectrum from T0-0.5 s to 0 s is
adequately fit by a simple power law function with
index 1.3 +/- 0.1 (chi squared 367 for 359 d.o.f.).

The event fluence (8-1000 keV) in this time interval is
4.1 (+/-0.2) E-7 erg/cm^2. The 128ms photon flux measured
starting from T0-0.28 s in the 8-1000 keV band
is 7.2 +/- 0.6 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081016B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8534
SUBJECT: GRB 081016b, SMARTS optical/IR observations
DATE:    08/11/20 22:50:32 GMT
FROM:    Bethany Cobb at UC Berkeley  <bcobb@astro.berkeley.edu>

B. E. Cobb (UC Berkeley) reports:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained optical/IR imaging of the error region of GRB 081016b
(Page et al. GCN 8381) with a mid-exposure time of 4.3 hours
post-burst (2008-10-17 00:06 UT).  Total summed exposure
times amounted to 36 minutes in I and 30 minutes in J.

No source is detected at the position of the X-ray
afterglow (Osborne et al. GCN 8383) to approximate
limiting magnitudes of I > 22.1 and J > 19.8. Magnitudes
are calibrated using Landolt standard stars in I, and 2MASS
stars in J.


GRB_name: GRB081118A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8535
SUBJECT: GRB081118 : optical upper limit
DATE:    08/11/21 09:12:42 GMT
FROM:    Hidenori Hayasi at Miyazaki U  <hayasi@astro.miyazaki-u.ac.jp>

H.hayasi, N.Ohmori, K.Kono H.Tanaka, R.Hara, M.Yamauchi, E.Sonoda,
(University of Miyazaki)

We have observed the field covering the error circle of 
GRB081118(GCN 8524, Hoversten et al.) 
with the unfiltered CCD camera on the 30-cm telescope at
University of Miyazaki.
The observation was started 14:57:54 UT, 38.1 min
after the Swift-BAT trigger time.

We have compared our data of 30 sec exposures
with the USNO-A2.0 catalog.there is no new source
at the reported position.
(GCN 8524, Hoversten et al. GCN 8526, Palmer et al. GCN 8528, D'Avanzo et al.) 


the upper limits are as follows:
--------------------------------------------------------------
Start(UT) End(UT) Num. of frames Limit (mag.)
--------------------------------------------------------------
15:35:58 15:36:28 1  16.7
15:35:58 16:11:50 32 17.6
---------------------------------------------------------------


GRB_name: GRB081121A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8536
SUBJECT: GRB 081121: ROTSE-III Detection of Optical Counterpart
DATE:    08/11/21 20:41:23 GMT
FROM:    Fang Yuan at ROTSE  <yuanfang@umich.edu>

F. Yuan (U Mich), W. Rujopakarn (Steward) report on behalf of the ROTSE 
collaboration:

ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, 
responded to GRB 081121 (Swift trigger 335105). The first image was at 
20:36:30.0 UT, 57.2 s after the burst (8.9 s after the GCN notice time). 
The unfiltered images are calibrated relative to USNO A2.0. We detect a 
11.6 magnitude, fading source with coordinates:

     05:57:06.1      -60:36:10.3    (J2000), with positional uncertainty 
of 1" or better

start UT     mag     mlim(of image)
----------------------------------
20:36:29.9     11.6     15.7 


This source is not visible in DSS (second epoch), 2MASS or the MPChecker 
database.

A jpeg image is available at 
http://www.rotse.net/images/gsb335105_3c00_img.jpg Note that the object 
marked 4 is the candidate in question.

Continuing observations are in progress.


GRB_name: GRB081121A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8537
SUBJECT: GRB 081121: Swift detection of a burst
DATE:    08/11/21 20:48:42 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

S. R. Oates (UCL-MSSL), W. H. Baumgartner (GSFC/UMBC),
A. P. Beardmore (U Leicester), N. Gehrels (NASA/GSFC),
O. Godet (U Leicester), S. T. Holland (CRESST/USRA/GSFC),
E. A. Hoversten (PSU), H. A. Krimm (CRESST/GSFC/USRA),
C. B. Markwardt (CRESST/GSFC/UMD), P. T. O'Brien (U Leicester),
C. Pagani (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL),
P. Schady (MSSL-UCL), M. Stamatikos (NASA/ORAU),
R. L. C. Starling (U Leicester), L. Vetere (PSU) and
H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team:

At 20:35:32 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081121 (trigger=335105).  Due to an Earth limb constraint
slew could not immediately slew to this burst. The BAT on-board 
calculated location is 
RA, Dec 89.264, -60.626 which is 
   RA(J2000) = 05h 57m 03s
   Dec(J2000) = -60d 37' 32"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single FRED
structure with a duration of about 15 sec, with overlying spikes. 
There may be continued low-level emission out to 100 seconds. 
The peak count rate was ~4000 counts/sec (15-350 keV), 
at ~1.5 sec after the trigger. 

Due to an observing constraint, Swift will not slew until 
T0+45.2 minutes. There will be no XRT or UVOT data until
this time. 

Burst Advocate for this burst is S. R. Oates (sro AT mssl.ucl.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081121A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8538
SUBJECT: GRB081121: Swift/UVOT observations
DATE:    08/11/21 22:19:23 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates  and P. Schady (MSSL-UCL) report on behalf of the Swift  
UVOT team:

The Swift/UVOT began observing the field of GRB081121 starting 2816  
seconds
after the BAT trigger (Oates et al., GCN 8537) with a White finding  
chart exposure
of 150 seconds. There is a candidate afterglow in the 2.7'x2.7' sub- 
image at

RA(J2000) = 05:57:06.19 = 89.27581
DEC(J2000) = -60:36:10.3 = -60.60286

with a 90%-confidence error radius of about 0.62 arc sec. This  
position is 0.7
arc sec. from the center of the XRT error circle and is consistent  
with the position
of the optical afterglow found by ROTSE-IIIc (Yuan el al., GCN 8536).

The estimated magnitude is 17.98 with a 1-sigma error of about 0.04. No
correction has been made for the expected extinction corresponding to  
E(B-V) of 0.05. 


GRB_name: GRB081121A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8539
SUBJECT: GRB 081121: Swift-BAT refined analysis
DATE:    08/11/22 00:09:10 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), S. R. Oates (UCL-MSSL),
D. M. Palmer (LANL), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-119 to T+271 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 081121 (trigger #335105)
(Oates, et al., GCN Circ. 8537).  The BAT ground-calculated position is
RA, Dec = 89.282, -60.612 deg, which is 
   RA(J2000)  =  05h 57m 07.7s 
   Dec(J2000) = -60d 36' 42.1" 
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 5%.
 
The mask-weighted light curve shows an approximately square-shaped pulse
with a trailing spike.  The pulse starts at ~T-10 sec and ends at ~T=15 sec.
There is a hint of low-level precursor emission starting before T-119 sec
(the beginning of the saved event-by-event data).
T90 (15-350 keV) is 14 +- 2 sec (estimated error including systematics).
 
The time-averaged spectrum from T-2.8 to T+12.9 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.43 +- 0.54, 
and Epeak of 123 +- 69 keV (chi squared 44.9 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 4.1 +- 0.3 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+6.94 sec in the 15-150 keV band is
4.4 +- 1.0 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.21 +- 0.12 (chi squared 52.0 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/335105/BA/


GRB_name: GRB081121A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8540
SUBJECT: GRB 081121: GROND observations 
DATE:    08/11/22 03:02:14 GMT
FROM:    Sebastian Loew at MPE  <sloew@mpe.mpg.de>

S. Loew, T. Kruehler and J. Greiner (all MPE Garching) report on behalf of 
the GROND team: 


We observed the field of GRB 081121 (Swift trigger #335105; Oates et al., 
GCN #8537) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, 
PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla 
Observatory (Chile). 


Observations started at 00:30 UT on November 22nd, 2008, 3.9 hr after the 
burst at a high airmass of 2.35, and are continuing. 


We detect the optical afterglow reported by Yuan et al. (GCN #8536) and 
Oates & Schady (GCN #8538) clearly in all filters. 


At a midtime of 3.9454 hours after the burst, we estimate the following 
preliminary magnitudes (all in AB system) in stacked images of 4 x 35s 
integration in g'r'i'z' and 24 x 10s integration in JHK: 


g' = 19.1
r' = 18.8
i' = 18.6
z' = 18.5
J = 18.4
H = 18.2
K = 18.1 


with typical errors of 0.2 mag, which are mostly due to a preliminary 
calibration using GROND zeropoints in g'r'i'z' and 2MASS field stars in JHK. 


GRB_name: GRB081121A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8541
SUBJECT: GRB 081121: Enhanced Swift-XRT position
DATE:    08/11/22 05:00:10 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 939 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 081121, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 89.2757, -60.6028 which is equivalent
to:

RA (J2000): 05h 57m 6.17s
Dec (J2000): -60d 36' 10.1"

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081121A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8542
SUBJECT: GRB 081121: Magellan Redshift
DATE:    08/11/22 05:21:25 GMT
FROM:    Edo Berger at Harvard  <eberger@cfa.harvard.edu>

E. Berger (Harvard) and M. Rauch (Carnegie) report:

"We obtained spectroscopic observations of the optical afterglow of GRB
081121 (GCNs 8536,8537) with the LDSS3 spectrograph on the Magellan/Clay
6.5-m telescope starting on 2008 Nov 22.16 UT.  The spectra cover the
wavelength range 3800-6500A.  We detect Ly-alpha absorption, as well as
aborption features corresponding to SiII, CII, SiIV, CIV, FeII, and AlII
at a redshift of z=2.512, which we consider the redshift of the burst.
Further analysis is in progress."


GRB_name: GRB081121A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8543
SUBJECT: GRB 081121: Swift-XRT refined analysis  
DATE:    08/11/22 11:43:57 GMT
FROM:    Olivier Godet at U.of Leicester  <og19@star.le.ac.uk>

O. Godet (U Leicester) and S. Oates (UCL-MSSL) on behalf the Swift-XRT 
team:

The Swift-XRT started observing the field of GRB 081121 (trigger number
335105, Oates et al., GCN Circ. 8537) at 2008-11-21 20:35:32 UT, 2.8 ks 
after the trigger. The best XRT position is the UVOT-enhanced position 
reported by Goad et al. (GCN Circ. 8541). This position is consistent with 
the optical positions reported by the Swift-UVOT and ROTSE III (Oates et 
al., GCN Circ. 8538; Yuan et al., GCN Circ. 8536).

The X-ray light curve presently spans 4.2 ks of photon counting (PC) mode 
data from T+2.8 ks to T+16 ks. The light curve shows an initial decay with 
a slope of 1.11 +0.06/-0.05 up to at least ~T+17 ks, followed by a steep 
decay up to ~T+20 ks and then a flatter decay with a slope of 0.25 
+0.62/-0.13.

The PC X-ray spectrum from the same interval can be well fit by an absorbed
power-law with a photon index of 1.99 +0.10/-0.09 and a column density of 
(9.7 +2.2/-2.0) x 10^20 cm^-2 (the Galactic value is 4.0 x 10^20 cm^-2 in 
the direction of the burst).  The observed 0.3-10.0 keV flux is (7.1 
+/-0.4) x 10^-11 erg cm^-2 s^-1 which corresponds to an unabsorbed flux of 
(9.0 +0.2/-0.5) x 10^-11 erg cm^-2 s^-1.

If the burst continues on the current plateau phase, the predicted count 
rate at T+1 day would be approximately 1.2 x 10^-1 count s^-1.

This is an official product of the Swift-XRT team.


GRB_name: GRB081121A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8544
SUBJECT: GRB081121: Refined Swift/UVOT observations
DATE:    08/11/22 12:13:02 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates (MSSL-UCL) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 081121,
2816s after the BAT trigger (Oates et al., GCN Circ. 8537). We detect the
optical afterglow in the white, v, b, u filters and marginally in the
uvw1 filter at the position:

RA(J2000)  =   5:57:06.15
DEC(J2000) = -60:36:10.0

with an estimated uncertainty of 0.6 arcsec (radius, 90% confidence).
This position is consistent with the UVOT-enhanced XRT position
and the position reported by ROTSE-IIIC (Yuan et al., GCN Circ. 8536).

The marginal detection of the optical afterglow in uvw1, and the lack
of a detection in the uvm2 and uvw2 filters is consistent with a redshift
of z=2.512 reported by Magellan (Berger and Rauch, GCN Circ. 8542).

The magnitudes and 3 sigma upper limits are reported below:

Filter    T_start (s) T_stop  Exposure      Mag/3sig UL
---------------------------------------------------------
white       2816       2965     147       17.93 +/- 0.04
v           2972       3172     197       17.58 +/- 0.08
b           3792       3992     197       18.26 +/- 0.07
u           3587       3787     197       17.62 +/- 0.06
uvw1        3383       3582     197       20.60 +/- 0.48 (2.3-sigma)
uvm2        3177       4813     393       > 20.09
uvw2        4203       11200    790       > 20.78
---------------------------------------------------------

The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E_{B-V} = 0.05 mag (Schlegel et al.,
1998, ApJS, 500, 525).  The photometry is on the UVOT flight system
described in Poole et al. (2008, MNRAS, 383,627).


GRB_name: GRB081121A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8546
SUBJECT: GRB081121: Fermi GBM detection
DATE:    08/11/22 23:06:39 GMT
FROM:    Colleen A. Wilson at NASA/MSFC/NSSTC  <colleen.wilson@nasa.gov>

Colleen A. Wilson-Hodge (NASA/MSFC) and Valerie Connaughton (UAH)
report on behalf of the Fermi GBM Team:

"At 20:35:27.5 UT on 21 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered on GRB 081121 (trigger 248992528/ 081121.858). This burst
triggered Swift-BAT 4 seconds later (Oates et al 2008, GCN 8537) and an
optical counterpart was detected with ROTSE-III (Yuan et al. 2008,
GCN 8536). The burst direction was 135 degrees from the Fermi pointing-axis
so the Fermi GBM sensitivity to this GRB is limited. Further analysis
is necessary to provide meaningful spectral information about this burst.

Final spectral analysis results will be published in the GBM GRB Catalog."


GRB_name: GRB081121A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8547
SUBJECT: GRB 081121, SMARTS optical/IR afterglow observations
DATE:    08/11/23 00:27:49 GMT
FROM:    Bethany Cobb at UC Berkeley  <bcobb@astro.berkeley.edu>

B. E. Cobb (UC Berkeley) reports:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained several epochs of optical/IR imaging of the
error region of GRB 081121 (GCN 8537, Oates et al.).  Each
epoch consisted of several dithered images in each filter, with
total summed exposure times of 180s in each of BRIJK and 120s
in each of H and V.

At a mid-exposure time of 2008-11-22 02:02 (5.4 hrs post-burst),
the GRB afterglow (GCN 8536, Yuan et al.) is detected with the
following magnitudes:
B = 19.34 +/- 0.04
R = 18.61 +/- 0.04
I = 18.21 +/- 0.04
J = 17.21 +/- 0.15
H = 17.05 +/- 0.15
K = 16.75 +/- 0.15

Observations were obtained under non-photometric conditions.  In optical,
these preliminary magnitudes are calibrated against several USNO-B1.0
stars in the field, so there is likely an additional photometric
calibration error of ~0.3 magnitudes.  In the IR, calibration is against 
2MASS stars.

Between 5.4 hrs and 8.7 hours post-burst, the afterglow decays
with an approximate optical decay rate of alpha~-1 (where
afterglow flux is proportional to t^alpha).


GRB_name: GRB081121A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8548
SUBJECT: Konus-Wind observation of GRB 081121
DATE:    08/11/23 16:07:29 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin,
D. Frederiks, P. Oleynik, D. Svinkin, M. Ulanov
and T. Cline, on behalf of the Konus-Wind team report:

The long GRB 081121 (Swift-BAT trigger #335105:
Oates et al., GCN 8537, Sakamoto et al. 8539) triggered
Konus-Wind at T0=74131.435 s UT (20:35:31.435).

The burst light curve shows a multipeaked structure with a total 
duration of ~18 s.

As observed by Konus-Wind the burst
had a fluence of 1.79(-0.31, +0.37)x10^-5 erg/cm2,
and a 256-ms peak flux measured from T0+16.368 s
of 2.60(-0.63, +0.70)x10^-6 erg/cm2/s
(both in the 20 keV - 7 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+16.640 s) is well be fitted (in the 20 keV - 7 MeV
range) by GRB (Band) model for which:
the low-energy photon index is alpha = -0.77(-0.14, +0.15),
the high energy photon index beta = -2.51(-0.66, +0.31),
the peak energy Ep = 248(-32, +38) keV (chi2 = 92.3/79 dof).

All the quoted errors are at the 90% confidence level.

Assuming z = 2.512 (Berger & Rauch, GCN 8542) and a standard
cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.27, Omega_\Lambda =
0.73, the isotropic energy release E_iso ~2.7x10^53 erg, the peak
luminosity (L_iso)_max ~ 1.4x10^53 erg/s, and Ep_rest ~870 keV.

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.rssi.ru/LEA/GRBs/GRB081121_T74131/


GRB_name: GRB081122A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8549
SUBJECT: GRB 081122: Fermi GBM detection
DATE:    08/11/24 17:05:13 GMT
FROM:    Sheila McBreen at MPE  <smcbreen@mpe.mpg.de>

Sheila McBreen (UCD/MPE) reports on behalf of the
Fermi GBM Team:

"At 12:28:12.21 UT on 22 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081122 (trigger 249049693 / 081122520).

The on-ground calculated location, using the GBM trigger
data, is RA = 338.7, DEC = +38.4 (J2000 degrees,
equivalent to 22 h 35 m, +38 d 24 '), with an uncertainty
of 1.2 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).

The angle from the Fermi LAT boresight is 21 degrees.
This event generated an Autonomous Repoint Recommendation from GBM,
which was accepted by the LAT and spacecraft. A 5 hour pointed mode
observation was initiated at the location of this burst.

The GBM light curve consists of 3 pulses
with a duration (T90) of about 26 s (8-1000 keV).
The time-averaged spectrum from T0-1 s to T0+26 s is
adequately  fit by a power law function with an exponential
high energy cutoff.  The power law index is -0.77 +/-0.07 and
the cutoff energy, parameterized as Epeak, is 200.7 +/-15.7  keV
(chi squared  431.7 for 353 d.o.f.).

A Band function fits the spectrum equally well
(chi squared 431.3 for 352 d.o.f.) with Epeak = 158.6 +/- 17.6 keV,
alpha = -0.63 +/- 0.15 , and beta = -2.24 +/- 0.20.

The event fluence (8-1000 keV) in this time interval is
(9.6 +/- 1.1) E-6 erg/cm^2 (Band model). The 64 ms
peak photon flux  measured  starting from T0+0.756 s
in the 8-1000 keV band is 30.0 +/- 3.0 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081118B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8550
SUBJECT: GRB 081118: Fermi GBM detection.
DATE:    08/11/24 18:06:29 GMT
FROM:    Narayana Bhat at U Alabama/Huntsville/GBM  <Narayana.Bhat@nasa.gov>

P. N. Bhat (UAH), R. D. Preece (UAH) and A.J. van der Horst (NASA/ORAU)
report on behalf of the Fermi GBM Team:

At 21:00:53.53 UT on 18 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081118B (trigger 248734854 / 081118876).

The on-ground calculated location, using the GBM trigger
data, is RA = 54.0, DEC = -50.4 (J2000 degrees,
equivalent to 03 h 36 m, 50 d 24'), with an uncertainty
of 2.9 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).

The angle from the Fermi LAT boresight is 41 degrees.

The GBM light curve consists of primarily 2 pulses.
It has a duration (T90) of about 20 s (8-1000 keV).
The time-averaged spectrum from T0-2.6 s to T0+27 s is
well fit by a Band function with Epeak = 41.2 +/- 3.9,
alpha = 0.8 +/- 0.5 and beta = -2.14 +/- 0.08.

The event fluence (8-1000 keV) in this time interval is
(1.12 +/- 0.61)E-7 erg/cm^2. The 1-sec peak photon flux
in the 8-1000 keV band is 0.67 +/- 0.37 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog.


GRB_name: GRB081120A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8551
SUBJECT: GRB 081120: Fermi GBM detection
DATE:    08/11/25 17:00:02 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs@mpe.mpg.de>

Elisabetta Bissaldi (MPE) reports on behalf of the Fermi GBM Team:


"At 14:49:34.57 UT on 20 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081120 (trigger 248885375 / 081120618).
The on-ground calculated location, using the GBM trigger
data, is RA = 205.4, Dec = -9.1 (J2000 degrees,
equivalent to 13h 42m, -09d 06'), with an uncertainty
of 6 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
The angle from the Fermi LAT boresight is 84 degrees.

The GRB light curve consists of two peaks and has a
duration (T90) of about 12 s (8-1000 keV).
The time-averaged spectrum from T0-3.072 s to T0+6.144 s
is best fit by a Band function with Epeak = 44 +/- 5 keV,
alpha = 0.4 +/- 0.5 and beta = -2.18 +/- 0.10
(chi squared 367 for 353 d.o.f.).

The event fluence (8-1000 keV) in this time interval is
(2.7 +/- 0.9)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+2.048 s in the 8-1000 keV band
is 5.1 +/- 1.6 ph/s/cm^2.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081124A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8552
SUBJECT: GRB 081124: Fermi GBM detection
DATE:    08/11/25 17:58:51 GMT
FROM:    Narayana Bhat at U Alabama/Huntsville/GBM  <Narayana.Bhat@nasa.gov>

P. N. Bhat (UAH) and A.J. van der Horst (NASA/ORAU)
report on behalf of the Fermi GBM Team:

At 01:26:10.85 UT on 24 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081124 (trigger 249182771 / 081124060).

The on-ground calculated location, using the GBM trigger
data, is RA = 336.5, DEC = -15.5 (J2000 degrees,
equivalent to 22 h 26 m, -15 d 32 '), with an uncertainty
of 3.5 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
 
The angle from the Fermi LAT boresight is 86 degrees.

The GBM light curve consists of 2 pulses
with a duration (T90) of about 35 s (8-1000 keV).
The time-averaged spectrum from T0-4.6 s to T0+25.1 s is
adequately fit by a Band function with Epeak = 22.8 +/- 0.7 keV,
alpha = -0.6 +/- 0.2, and beta = -2.83 +/- 0.08.

The event fluence (8-1000 keV) in this time interval is
(9.5 +/- 2.6)E-08 erg/cm^2. The 1-sec peak photon flux
in the 8-1000 keV band is 0.67 +/- 0.18 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog.


GRB_name: GRB081125A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8553
SUBJECT: GRB 081125: Fermi GBM detection
DATE:    08/11/26 17:28:43 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE) and E. Bissaldi (MPE) 
report on behalf of the Fermi GBM Team: 

"At 11:53:39.00 UT on 25 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081125 (trigger 249306820 / 081125496).

The on-ground calculated location, using the GBM trigger 
data, is RA = 42.3, DEC = -22.4 (J2000 degrees,
equivalent to 02h 49m, -22d 24'), with an uncertainty
of 1.0 degree (radius, 1-sigma containment, 
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
 
The angle from the Fermi LAT boresight is 126 degrees.

This burst was also independently detected by INTEGRAL SPI-ACS.

This GRB consists of a single peak with T90 (8-1000 keV) 
of about 15 s and T50 (8-1000 KeV) of about 4.4 s.
Since this GRB shows strong spectral evolution we fitted 
two time intervals:
The time-averaged spectrum from T0 to T0+3.200 s is  
best fit by a Band function with Epeak = 221 +/- 16 keV, 
alpha = 0.14 +/- 0.09, and beta = -2.34 +/- 0.22
(chi squared 354 for 357 d.o.f.).
The time-averaged spectrum from T0+3.200 s to T0+14.464 s is  
best fit by a power law function with an exponential
high energy cutoff. The power law index is -0.27 +/- 0.06
and the cutoff energy, parameterized as Epeak, is 257 +/- 12 keV
(chi squared 360 for 358 d.o.f.)

The event fluence (8-1000 keV) from T0+0.003 s to T0+14.464 s is
(4.91 +/- 0.16)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+2.176 s in the 8-1000 keV band 
is 27.0 +/- 2.7 ph/s/cm^2. 

The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081126A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8554
SUBJECT: GRB 081126: Swift detection of a burst
DATE:    08/11/26 21:58:18 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@astro.psu.edu>

R. Margutti (Univ Bicocca&OAB), A. P. Beardmore (U Leicester),
P. J. Brown (PSU), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC),
C. Guidorzi (INAF-OAB), S. T. Holland (CRESST/USRA/GSFC),
J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),
J. Mao (INAF-OAB), F. E. Marshall (NASA/GSFC), C. Pagani (PSU),
P. Romano (INAF-IASFPA), M. Stamatikos (NASA/ORAU),
T. N. Ukwatta (GSFC/GWU), L. Vetere (PSU) and H. Ziaeepour (UCL-MSSL)
report on behalf of the Swift Team:

At 21:34:10 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081126 (trigger=335647).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 323.542, +48.709 which is 
   RA(J2000) = 21h 34m 10s
   Dec(J2000) = +48d 42' 33"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a double-peaked
structure with a total duration of about 40 sec.  The two peaks are about
30 seconds apart. The peak count rate was ~7000 counts/sec (15-350 keV), 
at ~2 sec after the trigger. 

The XRT began observing the field at 21:35:16.0 UT, 65.7 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source with an enhanced position: RA, Dec 323.5150,
48.7097 which is equivalent to:
   RA(J2000)  = 21h 34m 3.60s
   Dec(J2000) = +48d 42' 34.9"
with an uncertainty of 2.3 arcseconds (radius, 90% containment). This
location is 64 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
4.13e+21 cm^-2 (Kalberla et al. 2005). 

The initial flux in the 2.5 s image was 7.07e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White   
filter  starting 75 seconds after the BAT trigger. No credible   
afterglow candidate has  been found in the initial data products. The
 2.7' x 2.7' sub-image covers 100% of  the XRT error circle. The   
estimated 3-sigma limiting magnitude is white > 21 mag.  No 
correction has   been made for the large, but uncertain extinction 
expected.  There is   a high proper motion 2MASS source inside the 
XRT error circle. 

Burst Advocate for this burst is R. Margutti (raffaella.margutti AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081126A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8555
SUBJECT: GRB 081126: TAROT Calern observatory optical observations
DATE:    08/11/26 23:51:32 GMT
FROM:    Alain Klotz at CESR-CNRS  <Alain.Klotz@free.fr>

Gendre B. (LAM-OAMP), Klotz, A. (CESR-OMP),
Boer M. (OHP-OAMP), Atteia J.L. (LATT-OMP) report:

We imaged the field of GRB 081126 detected by SWIFT
(trigger 335647) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 20.6s after the GRB trigger
(6.9s after the notice). The elevation of the field decreased
from 41 degrees above horizon and weather conditions
were very good.

The date of trigger : t0 = 2008-11-26T21:34:10

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT at the XRT position (Margutti et al. 2008
GCNC 8554) with a limiting magnitude of:
t0+20.6s to t0+80.6s : R > 16.6

The second image is 30.0s exposure in tracking mode:
t0+86.7s to t0+116.7s : R > 18.0

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.

N.B. Galactic coordinates are lon= 92.9 lat= -2.3
and the galactic extinction in R band is 2.1 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.


GRB_name: GRB081126A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8556
SUBJECT: GRB 081126: Enhanced Swift-XRT position
DATE:    08/11/27 01:30:41 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2152 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 081126, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 323.5147, +48.7098 which is equivalent
to:

RA (J2000): 21h 34m 3.54s
Dec (J2000): +48d 42' 35.2"

with an uncertainty of 1.8 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081126A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8557
SUBJECT: GRB 081126: Swift-BAT refined analysis
DATE:    08/11/27 02:23:00 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

G. Sato (ISAS), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), R. Margutti (U Bicocca&OAB), C. B. Markwardt (GSFC/UMD),
D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-120 to T+183 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 081126 (trigger #335647)
(Margutti, et al., GCN Circ. 8554).  The BAT ground-calculated position is
RA, Dec = 323.526, 48.714 deg, which is 
   RA(J2000)  =  21h 34m 06.3s 
   Dec(J2000) = +48d 42' 51.0" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 67%.
 
The mask-weighted light curve shows a small peak starting at ~T-30 sec,
peaking at ~T-18 sec, and returning almost to zero at T-7 sec, at which time
the second peak starts to rise.  It peaks at ~T+1.5 sec and reachs a maximum
at ~T+7 sec.  The third peak peaks at ~T+31.5 sec and ends at ~T+100 sec.
T90 (15-350 keV) is 54 +- 4 sec (estimated error including systematics).
 
The time-averaged spectrum from T-21.4 to T+45.9 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.27 +- 0.06.  The fluence in the 15-150 keV band is 3.3 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.75 sec in the 15-150 keV band
is 3.7 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/335647/BA/


GRB_name: GRB081126A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8558
SUBJECT: GRB 081126: optical observations
DATE:    08/11/27 02:54:03 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

Andreev M., Sergeev A.,  (Terskol Branch of Institute of Astronomy),  A. 
Pozanenko (IKI) on behalf of larger GRB follow up collaboration report:

We observed   the field of GRB 081126 detected by SWIFT (trigger 335647, 
Margutti et al GCN8554 ) with the Z-600  telescope of Mt. Terskol 
observatory.  A set of  90 s unfiltered exposures was taken starting (UT) 
Nov. 26 22:07:20.  In a combined image of  3x90 s we detect a new object 
not presented in DSS2(R), in near vicinity to the object of USNO-A2.0 
1350-14391154. A preliminary astrometry of the new object based on 
USNO-A2.0  is RA, Dec (J2000) = 21 34 03.56   +48 42 38.62 with 
uncertainty of 1", which is formally outside of  enhanced XRT position 
(Osborne et al GCN 8556).  It is not clear at this moment relation of the 
new object with GRB  081126.

A combined image can be found at 
http://grb.rssi.ru/GRB081126/GRB081126_z600.jpg


GRB_name: GRB081126A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8559
SUBJECT: GRB 081126: Swift/UVOT Observations
DATE:    08/11/27 02:58:03 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <sholland@milkyway.gsfc.nasa.gov>

S. T. Holland (CRESST/GSFC/USRA) and R. Margutti (Univ Bicocca & OAB)
report on the behalf of the Swift UVOT team:

       The Swift/UVOT observed the field of GRB 081126 starting 56 s
after the BAT trigger (Margutti, et al. 2008, GCN Circ. 8554).
Settled exposures started at T+75 s.  We do not find any new source,
relative to the DSS or 2MASS, or any variable source inside the
UVOT-enhanced XRT error circle (Osborne, et al. 2008, GCN Circ. 8556).
Preliminary 3-sigma upper limits for detecting a source in the
co-added images, using a 2.5 arcsecond radius circular aperture, are

Filter   T_start   T_stop   Exp(s)     Mag
------------------------------------------
  white        75      225     147    >21.3
     u        289      420     129    >20.1

     v       5161     5361     197    >19.7
     b       4546     6183     393    >20.9
     u       3133     5976     326    >20.7
   uvw1      5572     5771     197    >20.0
   uvm2      5366     5566     197    >19.8
   uvw2      4957     6398     199    >20.0
  white      4751     6388     393    >21.8
------------------------------------------

The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight corresponding to a
reddening of E_{B-V} = 0.78 mag (Schlegel, et al., 1998, ApJS, 500,
525).  All photometry is on the UVOT flight system described in Poole
et al. (2008, MNRAS, 383, 627).

      The 2MASS point source 21340333+4842361 is located 3.2 arcsec
north of the centre of the XRT error circle.  Our photometry is
slightly contaminated by an uncatalogued source approximately 2.6
arcsec northwest of the centre of the XRT error circle.  This source
appears to be extended and may be the host galaxy of GRB 081126.
Preliminary magnitudes are

Filter     Mag  Err
----------------------------------------
     v    19.2   0.3
     b    20.2   0.2
     u   >20.9        3-sigma upper limit
   uvw1  >20.1        3-sigma upper limit
   uvm2  >19.9        3-sigma upper limit
   uvw2  >20.1        3-sigma upper limit
  white   20.2   0.2
----------------------------------------

The detection in the b filter, combined with the lack of a detections
in the u and UV filters, is consistent with this source having a
redshift of approximately 2.8 < z < 4.5.  This corresponds to a
physical separation of approximately 18 proper kpc assuming a
cosmology with (H_0,Omega_matter,Omega_Lambda) = (70,0.3,0.7).


GRB_name: GRB081127A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8560
SUBJECT: GRB 081127: Swift detection of a burst
DATE:    08/11/27 07:25:04 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

J. Mao (INAF-OAB), W. H. Baumgartner (GSFC/UMBC),
P. A. Evans (U Leicester), C. Guidorzi (INAF-OAB),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
R. Margutti (Univ Bicocca&OAB), C. Pagani (PSU),
K. L. Page (U Leicester), D. M. Palmer (LANL),
T. Sakamoto (NASA/UMBC) and L. Vetere (PSU) report on behalf of the
Swift Team:

At 07:05:08 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081127 (trigger=335715).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 332.093, +6.859 which is 
   RA(J2000) = 22h 08m 22s
   Dec(J2000) = +06d 51' 33"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peak of 2
seconds on a broader plateau with a total duration of about 30 sec. 
The peak count rate was ~900 counts/sec (15-350 keV), at ~7 sec 
after the trigger. 

The XRT began observing the field at 07:07:10.8 UT, 121.9 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source with an enhanced position: RA, Dec
332.0646, 6.8504 which is equivalent to:
   RA(J2000)  = 22h 08m 15.49s
   Dec(J2000) = +06d 51' 01.6"
with an uncertainty of 2.4 arcseconds (radius, 90% containment). This
location is 106 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
6.86e+20 cm^-2 (Kalberla et al. 2005). 

The initial flux in the 2.5 s image was 9.56e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 130 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.09.  The XRT position is 9.8 arcseconds from the B = 13 USNO-B1.0 star 0968-0627697. 

Burst Advocate for this burst is J. Mao (jirong.mao AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081126A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8561
SUBJECT: GRB 081126: Swift-XRT refined analysis
DATE:    08/11/27 12:04:20 GMT
FROM:    Raffaella Margutti at U. di Milano Bicocca  <raffaella.margutti@brera.inaf.it>

R. Margutti (Univ. Bicocca & INAF-OAB) reports on behalf of the Swift 
XRT team:

We have analysed the first 5 orbits of Swift-XRT data obtained for GRB 
081126
(Margutti et al., GCN Circ. 8554), covering 100 s of Windowed Timing
(WT) and 9.1 ks of Photon Counting (PC) mode data, respectively, between 77
and 24 ks after the trigger.
The UVOT-enhanced XRT position was given by Osborne et al. in GCN Circ. 
8556.

The light-curve can be modelled by a double broken power-law,
with an initial decay of alpha_1= 1.2 +/- 0.2, a flat decay
of alpha_2= 0.6 +/- 0.1 and a final value of alpha_3= 2.1 +/- 0.2.
The two break times are around 200 and 9000 s, respectively.

A spectrum extracted from WT data can be modelled with an
absorbed power-law, with Gamma = 1.9 +/- 0.2 .
A spectrum extracted from PC data in the time interval  3-30 ks post 
trigger
can be modelled with an absorbed power-law, with Gamma = 2.0 +/- 0.1 and
a column density of NH = (5.0 +/- 0.7)x10^21 cm^-2, which is compatible with
the Galactic value in this direction (4.1x10^21 cm^-2).
The observed (unabsorbed) 0.3 -10 keV flux over this time
interval is 7.1x10^-12 (1.2x10^-11) erg cm^-2 s^-1.
For both spectra there is no strong evidence for intrinsic NH.
Uncertainties are given at 90% confidence.

If the light-curve continues to decay with alpha ~ 2, the count rate 24
hours after the burst is estimated to be 2.7x10^-3 count s^-1, which
corresponds to an observed flux of 1.4x10^-13 erg cm^-2 s^-1.

The results of the xrt automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00335647.

This is an official product of the Swift-XRT team.


GRB_name: GRB081126A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8562
SUBJECT: Konus-Wind observation of GRB 081126
DATE:    08/11/27 14:52:48 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin,
D. Frederiks, P. Oleynik, D. Svinkin, M. Ulanov,
and T. Cline, on behalf of the Konus-Wind team report:

The long GRB 081126 (Margutti et al., GCN 8554, Sato et al. GCN 8557) 
triggered Konus-Wind at T0=77649.857 s UT (21:34:09.857).

The burst light curve shows a precursor at ~T0-20 s and two main pulse 
at ~T0-3 s and ~T0+28 s with a total duration of ~60 s.

As observed by Konus-Wind the burst
had a fluence of 9.91(-1.46, +1.57)x10^-6 erg/cm2,
and a 256-ms peak flux measured from T0+1.808 s
of (1.65 +/- 0.36)x10^-6 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+41.216 s) is well fitted (in the 20 keV-2 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.82(-0.26, +0.32) ,
and Ep = 315(-71, +123)  keV (chi2 = 68.0/61 dof).
Fitting by GRBM (Band) model yields only an upper limit on
the high energy photon index: beta < -2.16.

All the quoted errors are at the 90% confidence level.

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.ru/LEA/GRBs/GRB081126_T77649/


GRB_name: GRB081127A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8563
SUBJECT: GRB 081127: Swift-BAT refined analysis
DATE:    08/11/27 15:36:17 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

M. Stamatikos (GSFC/ORAU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), J. Mao (INAF-OAB), C. B. Markwardt (GSFC/UMD),
D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-119 to T+183 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 081127 (trigger #335715)
(Mao, et al., GCN Circ. 8560).  The BAT ground-calculated position is
RA, Dec = 332.075, 6.858 deg, which is 
   RA(J2000)  =  22h 08m 18.0s 
   Dec(J2000) = +06d 51' 30.2" 
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 51%.
 
The mask-weighted light curve shows a single peak starting at ~T-30 sec,
peaking around T+0 sec, and ending at ~T+55 sec.
T90 (15-350 keV) is 37 +- 10 sec (estimated error including systematics).
 
The time-averaged spectrum from T-31.2 to T+8.8 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.10 +- 0.35.  The fluence in the 15-150 keV band is 4.9 +- 1.0 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-1.19 sec in the 15-150 keV band
is 0.6 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/335715/BA/


GRB_name: GRB081126A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8564
SUBJECT: GRB 081126: Confirmation of the Optical Afterglow 
DATE:    08/11/27 15:56:19 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <Stephen.T.Holland@nasa.gov>

S. T. Holland (CRESST/GSFC/USRA), P. A. Evans (U Leicester),
F. E. Marshall (NASA/GSFC), P. Schady (MSSL), and R. Margutti (U
Bicocca & OAB) report on the behalf of the Swift UVOT team:

      We confirm the optical afterglow of GRB 081126 reported by
Sergeev & Pozanenko (2008, GCN Circ. 8558). A re-examination of the
UVOT data shows that there is a fading source at

      RA (J2000)  21:34:03.59  =  323.51496 (deg)
     Dec (J2000) +48:42:38.3   =  +48.71064 (deg)

with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence,
statistical + systematic).  This is consistent with the XRT error
circle.  Preliminary photometry and 3-sigma upper limits for this
source are

Filter   T_start   T_stop   Exp(s)     Mag   Err
------------------------------------------------
  white        75      225     147     18.82 0.09
     u        289      420     127     18.17 0.13

     v       5161     5361     197     19.29 0.32
     b       4546     4746     197     20.20 0.28
     u       5778     5976     197    >20.4
   uvw1      5572     5771     197    >20.0
   uvm2      5366     5566     197    >19.6
   uvw2      4957     5156     197    >20.0
  white      4751     4951     197     20.33 0.21
------------------------------------------------

The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight corresponding to a
reddening of E_{B-V} = 0.78 mag (Schlegel, et al., 1998, ApJS, 500,
525).  All photometry is on the UVOT photometric system described in
Poole et al. (2008, MNRAS, 383, 627).  The detection in the u filter,
combined with the lack of detections in the UV filters, is consistent
with the afterglow having a redshift of approximately 2.4 < z < 3.8.
However, this result is uncertain due to the large Galactic reddening
along the line of sight to this source.

      The source identified in Holland & Margutti 2008, (GCN
Circ. 8559) as being possibly extended is consistent with the
catalogued position of the 2MASS point source 21340333+4842361.  The
separation between this 2MASS source and the afterglow is 3.2 arcsec.
Since the photometry of the 2MASS source and the afterglow are
consistent with both sources having at the same redshift it is
possible that the 2MASS source is the host galaxy.  Further
observations are encouraged to confirm or reject this hypothesis.

      Holland & Margutti 2008, (GCN Circ. 8559) misidentified the
optical afterglow as as the 2MASS point source 21340333+4842361.  We
apologize for any confusion caused by the misidentification in the
previous UVOT Circular on GRB 081126.


GRB_name: GRB081127A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8565
SUBJECT: GRB 081127: Enhanced Swift-XRT position
DATE:    08/11/27 16:23:08 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 3559 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 081127, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 332.0642, +6.8505 which is equivalent
to:

RA (J2000): 22h 08m 15.40s
Dec (J2000): +06d 51' 01.7"

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081127A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8566
SUBJECT: GRB 081127: Swift-XRT refined analysis
DATE:    08/11/27 17:42:56 GMT
FROM:    Jirong Mao at INAF-OAB  <jirong.mao@brera.inaf.it>

J. Mao, C. Guidorzi (INAF-OAB) and R. Margutti (Univ. Bicocca & 
INAF-OAB) report on behalf of the Swift XRT team:

We have analysed the first 4 orbits of Swift-XRT data obtained for GRB 
081127 (Mao et al., GCN Circ. 8560), covering from 128 to 219 s in 
Windowed Timing (WT) and from 220 s to 19.5 ks in Photon Counting (PC) 
mode data, respectively. The net exposures are 90 s and 9.4 ks for the 
WT and PC modes data, respectively.  The UVOT-enhanced XRT position was 
given by Beardmore et al. in GCN Circ. 8565.

The light curve shows an inital steep decay of index 5.6 until 420 s, 
then it shows a shallow decay with index of 0.6. After 13.3 ks the 
lightcurve shows a decay with an index of about 2.0. The WT spectrum can 
be fit with an absorbed power-law model with a photon index of 4.2 +- 
0.2 and an absorbing
equivalent hydrogen column density is (2.8 +- 0.3)e21 cm^-2, which is 
larger than the Galactic one, 6.7e20 cm^-2 (Kalberla et al.  2005). The 
observed (unabsorbed) 0.3-10 keV flux is 3.7(4.5)e-10 erg cm^-2  s^-1. 
The PC spectrum can be fit with an absorbed power-law model with a 
photon index of 2.3 +- 0.3 with an absorbing equivalent hydrogen column 
density compatible with the Galactic value.

If the light curve continues to decay with an index of 2.0, the count 
rate 24 hours after the burst will be 2.9e-4 c/s, corresponding to an 
absorbed flux of 9.9e-15 erg cm^-2 s^-1.

This is an official product of the Swift-XRT team.


GRB_name: GRB081127A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8567
SUBJECT: GRB 081127: Swift/UVOT Upper Limits
DATE:    08/11/27 18:03:49 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <sholland@milkyway.gsfc.nasa.gov>

S. T. Holland (CRESST/GSFC/USRA) and J. Mao (INAF-OAB) report on the
behalf of the Swift UVOT team:

       The Swift/UVOT observed the field of GRB 081127 starting 113 s
after the BAT trigger (Mao, et al. 2008, GCN Circ. 8560).  Settled
exposures started at T+131 s.  We do not find any new source, relative
to the DSS or 2MASS, or any variable source inside the UVOT-enhanced
XRT error circle (Beardmore, et al. 2008, GCN Circ. 8565).
Preliminary 3-sigma upper limits for detecting a source in the white
finding chart, and the co-added images, using a 2.5 arcsecond radius
circular aperture, are

Filter   T_start   T_stop   Exp(s)     Mag
------------------------------------------
  white       130      380      147   >21.3

     v        365   18,799     1473   >21.0
     b        466     7263      568   >21.4
     u        440   13,713     1246   >21.4
   uvw1       415   13,011     1276   >21.6
   uvm2       389   19,496     2004   >21.8
   uvw2       341   17,885     1473   >21.8
  white       490     7468      714   >22.2
------------------------------------------

The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight corresponding to a
reddening of E_{B-V} = 0.09 mag (Schlegel, et al., 1998, ApJS, 500,
525).  All photometry is on the UVOT photometry system described in
Poole et al. (2008, MNRAS, 383, 627).

      The B = 13.15 mag USNO-B1.0 star 0968-0627697 is located
approximately 4 arcsec north of the XRT position.  UVOT photometry at
the location of the X-ray source is contaminated by this star.


GRB_name: GRB081126A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8568
SUBJECT: GRB 081126: GRT Optical Observation
DATE:    08/11/27 18:37:17 GMT
FROM:    Takanori Sakamoto at NASA/GSFC  <takanori.sakamoto-1@nasa.gov>

T. Sakamoto (UMBC/GSFC), Y. Urata (Saitama U), D. Donato (ORAU/GSFC), 
N. Gehrels (GSFC), T. Okajima (JHU/GSFC), T. N. Ukwatta (GWU/GSFC) 

We observed the field of GRB 081126 detected by Swift (trigger #335647)
with the 14-inch Goddard Robotic Telescope (GRT) located at the 
Goddard Geophysical and Astronomical Observatory 
(http://cddisa.gsfc.nasa.gov/ggao/).  

Five set of 30s and 60s exposures were taken in the R filter starting 
from Nov. 27 03:58:18 (UT).  We do not detect any OT at the XRT 
position (Osborne et al. 2008 GCNC 8556).  The estimated 3-sigma 
upper limit of the combined image is ~17.5 mag using the USNO-B (r) catalog.


GRB_name: GRB081126A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8569
SUBJECT: GRB081126: Afterglow photometry from Crni Vrh
DATE:    08/11/28 00:08:26 GMT
FROM:    Herman Mikuz at OCV  <herman.mikuz@fmf.uni-lj.si>

J. Skvarc and H. Mikuz on behalf of PIKA observing program at Crni Vrh
Observatory.

We confirm variability of the source identified by Sergeev and Pozanenko
(GCN Circ. 8558).  The object was observed from Crni Vrh Observatory with
a 60 cm telescope using R filter and a CCD in about 5 arc-second seeing
conditions.  First 60 s exposure started at 2008-11-26 21:35:32 UT.  All
twenty exposures were of 60 s.  The table contains the time since the
Swift GRB detection to the middle of exposure in seconds, R magnitude and
formal 1-sigma magnitude error estimate.

Time     Mag     Err.
 [s]        [R]    [1-sigma]
----------------------------------
 112.1  17.02  0.02
 182.9  16.75  0.02
 253.9  16.81  0.02
 325.7  16.85  0.02
 396.5  16.93  0.02
 468.0  17.03  0.02
 538.8  17.07  0.02
 609.6  17.25  0.02
 680.4  17.25  0.02
 751.1  17.78  0.03
 821.5  17.64  0.03
 892.5  17.44  0.03
 963.3  17.79  0.03
1034.3  17.79  0.03
1105.1  17.65  0.03
1176.8  17.76  0.03
1247.6  17.77  0.03
1318.5  17.71  0.03
1389.3  17.77  0.03
1460.0  18.50  0.05


GRB_name: GRB081126A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8570
SUBJECT: GRB 081126:  Swift observations continuing
DATE:    08/11/28 04:39:39 GMT
FROM:    Neil Gehrels at GSFC  <gehrels@milkyway.gsfc.nasa.gov>

N. Gehrels (NASA-GSFC) on behalf of the Swift team

Swift observations of GRB 081127 have been terminated in favor of
the more interesting GRB 081126.  The observations of GRB 081126
will continue through November 29 and possibly longer.


GRB_name: GRB081128A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8571
SUBJECT: GRB 081128: Swift detection of a burst
DATE:    08/11/28 17:31:30 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

R. Margutti (Univ Bicocca&OAB), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), P. J. Brown (PSU),
D. N. Burrows (PSU), S. Campana (INAF-OAB), M. Capalbi (ASDC),
P.A. Curran (MSSL-UCL), P. A. Evans (U Leicester),
C. Guidorzi (INAF-OAB), S. T. Holland (CRESST/USRA/GSFC),
J. A. Kennea (PSU), W.B Landsman (GSFC), V. Mangano (INAF-IASFPA),
J. Mao (INAF-OAB), C. B. Markwardt (CRESST/GSFC/UMD),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
T. Sakamoto (NASA/UMBC), M. Stamatikos (NASA/ORAU),
R. L. C. Starling (U Leicester) and T. N. Ukwatta (GSFC/GWU) report
on behalf of the Swift Team:

At 17:18:44 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081128 (trigger=335895).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 20.798, +38.115, which is 
   RA(J2000)  =  01h 23m 12s
   Dec(J2000) = +38d 06' 54"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The TDRSS lightcurve for this image trigger
does shows a possible peak (or possibly background variation
during the slew). 

The XRT began observing the field at 17:22:02.2 UT, 197.5 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 20.80537, 38.12728 which
is equivalent to:
   RA(J2000)  = 01h 23m 13.29s
   Dec(J2000) = +38d 07' 38.2"
with an uncertainty of 4.0 arcseconds (radius, 90% containment). This
location is 48 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
6.09e+20 cm^-2 (Kalberla et al. 2005). 

The initial flux in the 2.5 s image was 8.04e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 206 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
No correction has been made for the expected extinction corresponding to
E(B-V) of 0.05. 

Burst Advocate for this burst is R. Margutti (raffaella.margutti AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081128A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8572
SUBJECT: GRB 081128: Optical observation of xinglong TNT
DATE:    08/11/28 19:34:24 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

J.Wang, L.P. Xin, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng,
W.K. Zheng on behalf of EAFON report:

We began to observe GRB081128 (Margutti et al., GCN 8571) 
with Xinglong TNT telescope at 17:25:16(UT),6min32s 
after the burst.A series of white, R band have been obtained.
After combined 10*20s white band data (without bias,flat-field
correction) and made a preliminary analysis,
a marginal object within the 
errorbar of XRT was detected with an estimated 
brightness of R ~ 20.9+/- 0.44 calibrated to USNO-B1.0,
at the mean time of 500s after the burst.

We are not sure whether it is the OT or not, because of 
lack of flat images at the moment. 
We will reduce it tomorrow and give a more precise 
result and analysis.

This message may be cited.

For more information about Xinglong GRBs Follow-up 
observations, please visit the website:
http://www.xinglong-naoc.org/grb/


GRB_name: GRB081128A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8573
SUBJECT: GRB 081128: Enhanced Swift-XRT position
DATE:    08/11/28 20:31:18 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2095 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 081128, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 20.8041, +38.1271 which is equivalent
to:

RA (J2000): 01h 23m 12.98s
Dec (J2000): +38d 07' 37.5"

with an uncertainty of 1.8 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081128A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8574
SUBJECT: GRB 081128: Swift-BAT refined analysis
DATE:    08/11/28 20:59:47 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

J. Tueller (GSFC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), R. Margutti (U Bicocca&OAB), C. B. Markwardt (GSFC/UMD),
D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+303 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 081128 (trigger #335895)
(Margutti, et al., GCN Circ. 8571).  The BAT ground-calculated position is
RA, Dec = 20.800, 38.123 deg, which is 
   RA(J2000)  =  01h 23m 12.0s 
   Dec(J2000) = +38d 07' 23.8" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 74%.
 
The mask-weighted light curve shows two overlapping peaks.  The first start
probably before the object comes into the BAT FOV at T-95 sec and peaks at 
~T=18 sec.  The second peak peaks around T=35 sec and ends at ~T+90 sec.
T90 (15-350 keV) is 100 +- 11 sec (estimated error including systematics).
 
The time-averaged spectrum from T-69.0 to T+62.7 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.08 +- 0.45, 
and Epeak of 45.1 +- 4.7 keV (chi squared 34.6 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 2.3 +- 0.2 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+17.60 sec in the 15-150 keV band is
1.3 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.98 +- 0.09 (chi squared 48.9 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/335895/BA/


GRB_name: GRB081128A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8575
SUBJECT: GRB081128 : Lulin optical follow-ups
DATE:    08/11/29 02:33:48 GMT
FROM:    Yuji Urata at Saitama U  <urata@asiaa.sinica.edu.tw>

C.S Lin (NCU), Y. Urata (Saitama U/ASIAA) and K.Y Huang (ASIAA)
on behalf of EAFON report:

"We observed the error region of GRB081128 (Margutti et al. GCN8571)
using the Lulin 1m telescope from 10.9 min after the burst. The R-band
images show possible optical afterglow as reported by Wang et al (GCN
8572) at RA=01:23:13.070 Dec=+38:07:38.77 with R=20.4 magnitude.
However, the source shows no variability during our observations (10.9
-- 33.3 min after the burst).

 Time (min)  Rmag, error
 10.9        20.4  0.1
 33.3        20.4  0.1

There is no other optical sources in the XRT error region 
down to the R~21.4."


GRB_name: GRB081128A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8576
SUBJECT: GRB081128: optical observations
DATE:    08/11/29 05:28:34 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

M. Andreev, A. Sergeev,  (Terskol Branch of Institute of Astronomy),  A. 
Pozanenko (IKI) on behalf of larger GRB follow up collaboration report:

We observed   the field of GRB 081128 detected by SWIFT (Margutti  et al, 
GCN 8571) with the Z-600  telescope of Mt. Terskol observatory.  A set of 
90 s unfiltered exposures was taken starting (UT) Nov. 28 17:37.  In a 
combined image of  first exposures (3x90 s) we do not detect any new 
object  in the  enhanced XRT (Evans, et al, GCN 8573) up to 18.5m. In a 
combined image 18x90 s at mid time (UT) Nov. 28 18:08 we detect a faint 
object at coordinates (J2000) RA, Dec =  01 23 13.02 +38 07 38.1 with 
brightness of ~20.3m. A photometry and astrometry is preliminary and based 
on USNO-A2.0 and R mag of USNO-A2.0. Our photometry at ~ 50 min after 
burst is consistent with the photometry reported early (Wang et al, GCN 
8572, Lin et al, GCN 8575) suggesting non fading source within XRT error 
box.


GRB_name: GRB081128A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8577
SUBJECT: GRB 081128: Liverpool Telescope afterglow confirmation
DATE:    08/11/29 11:21:44 GMT
FROM:    Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>

C. Guidorzi (INAF-OAB), N. Tanvir (U. Leicester), I.A. Steele, R.J. Smith,
C.G. Mundell, D. Bersier (Liverpool JMU), A. Gomboc (U. Ljubljana)
report on behalf of a larger collaboration:

On 2008 November 28 (22:16:14 UT) we began observing the field of GRB 081128
(Margutti et al. GCN Circ. 8571) with the Liverpool Telescope.
Observations consisted of two sequences of 6x300s exposures acquired
using the SDSS-i and SDSS-r filters, respectively.

In our coadded frame we detect a single source inside the refined XRT
error box (Evans et al. GCN Circ. 8573) at the position
RA(J2000)=01:23:13.05, Dec(J2000)=+38:07:38.7 (0.6" error radius)
consistent with the optical candidate reported by Lin et al. (GCN Circ.
8575) and Andreev et al. (GCN Circ. 8576).
We found the following magnitude for this object:


Telescope   Filter  T_mid[hr]   Exposure[s]    M_lim
-----------------------------------------------------------
LT          SDSS-r    6.66        6x300        21.9 +/- 0.2
-----------------------------------------------------------

The calibration was performed using the R2 magnitudes of several USNOB-1
catalogue field objects. Compared with the value reported by Lin et al.
(GCN Circ. 8575), our measurement shows that the candidate has faded
between the two epochs.
There also appears to be a neighbouring source just outside the XRT
error circle, which might be a host galaxy.


GRB_name: GRB081128A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8578
SUBJECT: GRB 081128: Swift-XRT refined analysis
DATE:    08/11/29 12:13:25 GMT
FROM:    Raffaella Margutti at U. di Milano Bicocca  <raffaella.margutti@brera.inaf.it>

R. Margutti (Univ. Bicocca & INAF-OAB), J.Mao (INAF-OAB) and C. Guidorzi 
(INAF-OAB)
report on behalf of the Swift XRT team:

We have analysed the first 4 orbits of Swift-XRT data obtained for
GRB 081128 (Margutti et al., GCN Circ.8571), covering 100 s of
Windowed Timing (WT) and 6 ks of Photon Counting (PC) mode data,
respectively, between 195 s and 35 ks after the trigger.
The UVOT-enhanced XRT position was given by Evans et al. in GCN Circ.8573.

The light-curve can be modelled by a broken power-law, with a steep
decay of alpha_1=4.1  0.2 and a break time of about 1000 s.  
The decay then flattens to alpha_2=0.4  0.1

The spectrum extracted from WT data can be poorly modelled with an
absorbed simple power-law, with Gamma =3.7  0.4 and
NH = (2.7  0.1)x1021 cm-2 (P-value=5x10-5).
The fit is statistically improved adding a black body component of
temperature T=0.15  0.03 keV. In this case we obtain Gamma= 1.8  0.6 and
NH = (1.2  0.1)x1021 cm-2 (P-value=0.4).
This result makes GRB 081128 similar to the sample considered by
Moretti et al.,2008 A&A 478,409.

The spectrum extracted from PC data in the time interval 0.3-35 ks
can be modelled with an absorbed power-law, with Gamma = 1.7  0.2
and a column density of NH = (0.5  0.4)x1021 cm-2,which is
compatible with the Galactic value in this direction (0.6x1021 cm-2).
The observed (unabsorbed) 0.3 -10 keV flux over this time
interval is 3.0x10-12 (3.3x10-12) erg cm-2 s-1.
Uncertainties are given at 90% confidence.

If the light-curve continues to decay with alpha ~0.4, the count rate 24
hours after the burst is estimated to be 9.2x10-3 count s-1, which
corresponds to an observed flux of 4x10-13 erg cm-2 s-1.

The results of the xrt automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00335895.

This is an official product of the Swift-XRT team.


GRB_name: GRB081122B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8579
SUBJECT: GRB 081122B: Fermi GBM Detection
DATE:    08/11/29 15:13:15 GMT
FROM:    Valerie Connaughton at MSFC  <valerie@nasa.gov>

Valerie Connaughton (UAH) and Sheila McBreen (UCD/MPE)  
report on behalf of the Fermi GBM Team:

"At 14:43:26.23 UT on 22 November 2008, the Fermi Gamma-Ray Burst
 Monitor triggered and located GRB 081122B
(trigger  249057807 / 081122614).

The on-ground calculated location, using the GBM trigger
data, is RA = 151.4, DEC = -2.1 (J2000 degrees,
equivalent to 10 h 06 m, -02 d 06 '), with an uncertainty
of 11.2 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
 
The angle from the Fermi LAT boresight is 52 degrees.

The GBM light curve shows this is a short burst with a
single spike of duration (T90) of about 0.3 s (50 - 300 keV).
The time-averaged spectrum from T0-0.13 s to T0+0.13 s is
best fit by a simple power law function with index -1.5 +/- 0.1
(chi squared 372 for 484 d.o.f.).

The event fluence (50 - 300 keV) in this time interval is
(7.9 +/- 0.1)E-8 erg/cm^2. The 256 ms photon flux measured
starting from T0-0.128 s in the 50 - 300 keV band
is 1.6 +/- 0.1 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081128A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8581
SUBJECT: GRB081128: Swift/UVOT Upper Limits
DATE:    08/11/29 21:22:41 GMT
FROM:    Peter Brown at PSU  <pbrown@astro.psu.edu>

P. J. Brown (PSU) and R. Margutti (Univ. Biococca & OAB)
report on behalf of the Swift UVOT team:

The Swift/UVOT observed the field of GRB 081128 starting 206 s
after the BAT trigger (Margutti et al., GCN Circ. 8571).
We do not detect any source inside the UVOT-enhanced XRT
error circle (Evans, et al., GCN Circ. 8573)
down to the following 3-sigma upper limits in the
finding chart and co-added images:

Filter     T_start   T_stop    Exp(s)  Mag
------------------------------------------
  white       207      356      150   >20.9

  white       207      959      308   >21.3
     v        363     5643      247   >19.4
     b        462      826       58   >19.6
     u        437      801       58   >19.3
   uvw1       413      777       58   >19.0
   uvm2       388      752       58   >18.6
   uvw2       512     4429      236   >19.9

   white    10015    34512      625   >21.4
     v      27370    75499     3535   >21.0
-----------------------------------------

The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight corresponding to a
reddening of E(B-V) = 0.05 mag (Schlegel, et al., 1998, ApJS, 500,
525).  All photometry is on the UVOT photometry system described in
Poole et al. (2008, MNRAS, 383, 627).


GRB_name: GRB081128A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8584
SUBJECT: GRB 081128A: optical observations
DATE:    08/11/30 18:00:48 GMT
FROM:    Igor Volkov at Asro.Inst.Slovak Acad.Sciences  <volkov@ta3.sk>

On 2008 November 28 (19:55:36 UT) I began observing the field of GRB 081128A
(Margutti et al. GCN Circ. 8571) with the 0.5m reflector and ST-10XME CCD
camera of Stara Lesna (Slovak Republic) observatory. Observations
consisted of one sequence of 7x300s exposures acquired in standard Rc
system.
In my coadded frame it was not possible to detect a single source inside
the refined XRT error box (Evans et al. GCN Circ. 8573) at the position
RA(J2000)=01:23:13.05, Dec(J2000)=+38:07:38.7 with S/N rate more than 5,
which corresponds to Rc = 20.7. But on the level S/N = 3 one could measure
the object with Rc = 21.6+/- 1.1. So I declare Rc = 20.7 as an upper limit
to the source which could be found within error box. The time of the
middle of the sequence was 20:10:52 UT.
The calibration was performed using the Rc magnitudes of SAO53150 (Scopal
A&A 401, L17â€“L20, 2003) measured just after GRB 081128A observations. The
nearby to error box star GSC 2813 1599 = 12.66Rc +/-0.04 from this
calibration.
This study was supported by the SAI scholarship.

Igor Volkov, Astronomical Institute of the Slovak Academy of Sciences, 059
60 TatranskÃ¡ Lomnica, Slovak Republic; e-mail: volkov@ta3.sk

[GCN OPS NOTE(30nov08): This circular was delayed ~17 hrs until the author
was added to the vetted list.]


GRB_name: GRB081130A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8585
SUBJECT: GRB 081130: MASTER VWF prompt optical observations Fermi GRB
DATE:    08/12/01 10:49:09 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski, N.Shatskiy, N.Tyurina, 
D.Kuvshinov, A.Kuznetcov
Sternberg Astronomical Institute, Moscow State University

A. Tlatov, A.Parkhomenko
Kislovodsk Solar Station of the Pulkovo Observatory

V.Krushinski, I.Zalognikh
Ural State University, Kourovka


S.Yazev, K.Ivanov
Irkutsk State University


One of the four  MASTER Very Wide Field Cameras located at Kislovodsk
(http://apollo.sai.msu.ru/, D=50 mm, 4x1000 square degrees, 35'' per pix) has 
observed the 70% Fermi large error box  (Trig Nuber 249750316) with 5s 
exposures during all night without time gap between images.

These unfiltered images are calibrated relative to Tycho stars (V).
The magnitued limit of the each emage is  ~11m. 
Note: the GRB was at the edge of the  camera FOW.

The message may be cited.

mailto: lipunov@sai.msu.ru


GRB_name: GRB081129A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8586
SUBJECT: GRB 081129: Fermi GBM detection
DATE:    08/12/01 11:08:37 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE)  
reports on behalf of the Fermi GBM Team: 

"At 03:52:04.26 UT on 29 November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081129 (trigger 249623525 / 081129161).

The on-ground calculated location, using the GBM trigger 
data, is RA = 55.0, DEC = -63.0 (J2000 degrees, 
equivalent to 03h 40m, -63d 00'), with an uncertainty 
of 1.9 degrees (radius, 1-sigma containment, 
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
 
The angle from the Fermi LAT boresight is 118 degrees.

This burst was also independently detected by INTEGRAL SPI-ACS.

The GBM light curve contains 2 peaks and has a duration (T90) 
of about 59 s (8-1000 keV) and (T50) of about 17 s (8-1000 keV).
The time-averaged spectrum from T0+0.003 s to T0+59.521 s is 
best fit by a Band function with Epeak = 150 +/- 30 keV, 
alpha = -0.5 +/- 0.2, and beta = -1.84 +/- 0.08
(chi squared 253 for 233 d.o.f.).
The event fluence (8-1000 keV) in this time interval is 
(2.0 +/- 0.3)E-05 erg/cm^2. The 1-sec photon flux measured 
starting from T0 s in the 8-1000 keV band 
is 14 +/- 3 ph/s/cm^2.

The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081126A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8587
SUBJECT: VLA Radio upper limit on GRB 081126
DATE:    08/12/01 16:57:26 GMT
FROM:    Poonam Chandra at U Virginia/NRAO  <pc8s@virginia.edu>

Poonam Chandra (RMC) and Dale A. Frail (NRAO) report on
behalf of the Caltech-NRAO-Carnegie GRB Collaboration:

"We used the Very Large Array to observe the field of view toward
optically bright GRB 081126 (GCN 8554) at a frequency of 8.46 GHz
on 2008 Nov 28.97 UT. The GRB radio afterglow is undetected and
the peak radio flux at the UVOT position (GCN 8564) is 24  64 uJy.

The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."


GRB_name: GRB081126A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8589
SUBJECT: GRB 081126: Fermi GBM detection
DATE:    08/12/01 17:28:29 GMT
FROM:    Narayana Bhat at U Alabama/Huntsville/GBM  <Narayana.Bhat@nasa.gov>

P. N. Bhat (UAH) and A.J. van der Horst (NASA/ORAU)
report on behalf of the Fermi GBM Team:

"At 21:34:09.06 UT on 26th November 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB081126 (trigger 249428050 / 081126899) which was
also detected by the SWIFT-BAT (Margutti et al. 2008, GCN Circular 8554)
 
The angle from the Fermi LAT boresight is 18 degrees.

This burst was also independently detected by INTEGRAL SPI-ACS and
Konus/Wind (Golenetskii et al., 2008, GCN Circular 8562).

The GBM light curve consists of two pulses separated by
about 30 s with almost no emission in between. There is
also a weak untriggered emission at about T0-20 s.
The burst duration (T90) is about 56 s (8-1000 keV).
The time-averaged spectrum of the first pulse from T0 s to T0+11 s is
well fit by a Band function with Epeak = 192 +/- 74 keV,
alpha = -0.3 +/- 0.4, and beta = -1.6 +/- 0.1.(chi squared 547 for 487
d.o.f.) 

Similarly the second pulse from about 20 s to 40 s is also
well fit by a Band function with Epeak = 162 +/- 77 keV,
alpha = -0.3 +/- 0.5, and beta = -1.6 +/- 0.1.
(chi squared 539 for 487 d.o.f.). The time averaged spectrum of the
entire burst is well fit by a Band function with Epeak = 176 +/- 84 keV,
alpha = -0.3 +/- 0.5, and beta = -1.7 +/- 0.1. (chi squared 464 for 487
d.o.f.)

The event fluences (8-1000 keV) in the two pulses are
(2.7 +/- 0.8)E-07 erg/cm^2 and (1.9 +/- 0.8)E-07 erg/cm^2
respectively. The 1-sec peak photon fluxes in the 8-1000 keV
band in the two pulses are 1.3+/- 0.4 ph/s/cm^2 and 1.0 +/- 0.4
ph/s/cm^2 respectively. The total event fluence (8-1000 keV) is
(1.5 +/- 0.6)E-07 erg/cm^2. The 1-sec peak photon fluxes in the 8-1000 keV
band in the two pulses are 0.7+/- 0.3 ph/s/cm^2
 

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081126A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8590
SUBJECT: GRB 081126: afterglow photometry
DATE:    08/12/01 21:39:02 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

M. Andreev, A. Sergeev, (Terskol Branch of Institute of Astronomy), A. 
Pozanenko (IKI) on behalf of larger GRB follow up collaboration report:

We observed the field of GRB 081126  (Margutti et al GCN 8554) with the 
Z-600 telescope of Mt. Terskol observatory. Series of unfiltered   exposures 
were taken between Nov.26 (UT) 21:48:45 - 22:34:35. A photometry of the 
afterglow (Andreev et al, GCN 8558, Holland et al, GCN 8564) against 
USNO-B1.0 (R2) field stars is following

T0+   Exp.      Mag.  Err.
mid     s

 940  1015     18.6  0.2
1203  10x30     18.8  0.2
1635   5x90     19.3  0.3
2375   7x90     19.8  0.3
2920   5x90     20.1  0.3

The photometry is compatible with a power law decay of a light curve with 
index of ~ -0.66. 


GRB_name: GRB081130A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8592
SUBJECT: GRB 081130: Fermi GBM detection
DATE:    08/12/02 16:10:20 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE)  
reports on behalf of the Fermi GBM Team: 

"At 05:04:40.72  UT on 30 November 2008, the Fermi Gamma-Ray Burst Monitor 
triggered and located GRB 081130 (trigger 249714281 / 081130212).
The on-ground calculated location, using the GBM trigger 
data, is RA = 37.0, DEC = +46.0 (J2000 degrees, 
equivalent to 02h 28m, 46d 00'), with an uncertainty 
of 5.0 degrees (radius, 1-sigma containment, 
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).

The angle from the Fermi LAT boresight is 90 degrees.

Since the source is soft and weak, the time-averaged spectrum 
is poorly constrained."


GRB_name: GRB081130B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8593
SUBJECT: GRB 081130B: Fermi GBM detection
DATE:    08/12/02 21:26:01 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <Alexander.J.VanDerHorst@nasa.gov>

A.J. van der Horst (NASA/MSFC/ORAU) reports on behalf of the Fermi GBM 
Team:

"At 15:05:15.72 UT on 30 November 2008, the Fermi Gamma-ray Burst Monitor
(GBM) triggered and located GRB 081130 (trigger 249750316 / 081130.629).
The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 14.1, Dec = +4.2 (J2000 degrees, equivalent to J2000 0h 56m,
+4d 10'), with a statistical uncertainty of 3.5 degrees (radius, 1-sigma
containment, statistical only; there is additionally a systematic error
which is currently estimated to be 2 to 3 degrees).
The angle from the Fermi LAT boresight is 66 degrees.

The GBM light curve shows a spike of ~12 seconds and a possible precursor
at ~T0-28 seconds. The time-averaged spectrum from T0-0.8s to T0+7.4s is
best fit by a power-law function with an exponential high-energy cutoff.
The power-law index is -0.77 +/- 0.12 and the cutoff energy, parameterized
as Epeak, is 152 +/- 17 keV. The fluence (50-300 keV) in this time
interval is (1.3 +/- 0.1)E-6 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.3s in the 50-300 keV band is 1.8 +/- 0.3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081128A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8594
SUBJECT: GRB 081128: optical observation
DATE:    08/12/03 12:34:20 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Sergeev (CrAO), V. Rumyantsev (CrAO), A. Pozanenko (IKI) on behalf of 
larger GRB follow up collaboration report:

We observed the error box of Swift GRB 081128 (Margutti  et al, GCN 8571) 
in I band on Nov. 28 between (UT) 20:20:28 - 20:31:16 with AZT-8 telescope 
of CrAO. Inside the refined XRT error box (Evans et al. GCN 8573) we do 
not detect the source reported as possible afterglow (Wang et al, GCN 
8572; Lin et al, GCN 8575; Andreev et al, GCN 8576; Guidorzi et al, GCN 
8577). The photometry of the combined image is following:

T0+    Filter, Exposure, mag.
(h)             (s)

3.23  I        5x120     >20.0 (3 sigma)


GRB_name: GRB081203A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8595
SUBJECT: GRB 081203: Swift detection of a burst with a bright optical counterpart
DATE:    08/12/03 14:09:33 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

A. M. Parsons (GSFC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU),
P.A. Curran (MSSL-UCL), P. A. Evans (U Leicester),
O. Godet (U Leicester), C. Gronwall (PSU),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
V. La Parola (INAF-IASFPA), V. Mangano (INAF-IASFPA),
J. Mao (INAF-OAB), R. Margutti (Univ Bicocca&OAB),
F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester),
J. P. Osborne (U Leicester), C. Pagani (PSU),
K. L. Page (U Leicester), B. Preger (ASDC), P. Romano (INAF-IASFPA),
B. Sbarufatti (INAF-IASFPA), R. L. C. Starling (U Leicester),
E. Troja (INAF-IASFPA), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU)
report on behalf of the Swift Team:

At 13:57:11 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081203 (trigger=336489).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 233.033, +63.498 which is 
   RA(J2000)  =  15h 32m 08s
   Dec(J2000) = +63d 29' 54"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a two peak
structure with a duration of about 70 sec.  The peak count rate
was ~4000 counts/sec (15-350 keV), at ~32 sec after the trigger. 

The XRT began observing the field at 13:58:34.7 UT, 83.1 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 233.0316, +63.5207 which is equivalent to:
   RA(J2000)  = 15h 32m 07.58s
   Dec(J2000) = +63d 31' 14.5"
with an uncertainty of 5.9 arcseconds (radius, 90% containment). This
location is 81 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 92 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 15:32:07.58 = 233.03158
  DEC(J2000) = +63:31:14.9  = 63.52081
with a 90%-confidence error radius of about 0.74 arc sec. This position is 0.4
arc sec. from the center of the XRT error circle. The estimated magnitude is
14.55 with a 1-sigma error of about 0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.02. 

Burst Advocate for this burst is A. M. Parsons (parsons AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081203A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8596
SUBJECT: GRB081203: optical observation
DATE:    08/12/03 15:01:11 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

M. Andreev, A. Sergeev,  (Terskol Branch of Institute of Astronomy),  Ju. 
Babina  (CrAO) A. Pozanenko (IKI) on behalf of larger GRB follow up 
collaboration report:

We observed   the field of GRB 081203 detected by SWIFT ( with the Z-600 
telescope of Mt. Terskol observatory.  A few first unfiltered images confirm 
the presence bright afterglow detected by UVOT  Parsons  et al, GCN Parsons) 
in coordinates (J2000) 15 32 07.75 +63 31 15.04. A preliminary photometry 
at Dec.03 (UT) 14:29:30 against USNO-A2.0 (R) is 14.9 mag. Observation is 
continuing.


GRB_name: GRB081130B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8597
SUBJECT: GRB 081130B: MASTER prompt optical observations
DATE:    08/12/03 17:13:15 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski, N.Shatskiy, N.Tyurina, 
D.Kuvshinov, P.Balanutsa
Sternberg Astronomical Institute, Moscow State University

A. Tlatov, A.V. Parhomenko 
Kislovodsk Solar Station of the Pulkovo Observatory

V.Krushinski, I.Zalognikh
Ural State University, Kourovka


S.Yazev, K.Ivanov
Irkutsk State University

One of the four  MASTER Very Wide Field Cameras located at Kislovodsk
(http://apollo.sai.msu.ru/, D=50 mm, 4x1000 square degrees, 35'' per pix)
has observed  Fermi  error box  (A.J. van der Horst, GCN Circ 8593) with 
5s exposures during all night without time gap between images (Gorbovskoy 
et al., GCN 8585).

These unfiltered images are calibrated relative to Tycho stars (V).
The magnitude limit of the each emage is  ~11m.

Now we present results final result.

We do not detect any new source inside error box  (A.J. van der Horst, 
GCN Circ 8593)  brighter than 12.0 mag before and 
after trigger time.

The optical fluence during the 15s-GRBurst is limited by

                      <= 1.5 x 10_-9 erg/cm_2

excluding possible  absorbtion.
The fluence (50-300 keV) in this time
interval is (1.3 +/- 0.1)E-6 erg/cm^2 (A.J. van der Horst, GCN Circ 8593).

So:

Optical Fluence/Gamma-Fluence(50-300 keV) ~ < 1/1000

The ratio for GRB080319B is

Optical Fluence/Gamma-Fluence(15-150 keV) ~ 1/25

(Naked Eye GRB, Racusin, Karpov et al., Nature, vol.455, 183, 2008).


The video and other info  are available at
http://observ.pereplet.ru/images/GRB081130B/grb_film.html

Note: the GRB was at the edge of the FOW.

The message may be cited.

mailto: lipunov@sai.msu.ru


GRB_name: GRB081203A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8598
SUBJECT: GRB 081203: Enhanced Swift-XRT position
DATE:    08/12/03 18:31:36 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2654 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 081203, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 233.0327, +63.5207 which is equivalent
to:

RA (J2000): 15h 32m 7.84s
Dec (J2000): +63d 31' 14.4"

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081203A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8599
SUBJECT: GRB 081203A: Swift-BAT refined analysis
DATE:    08/12/03 18:41:04 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

T. N. Ukwatta (GWU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL),
A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+482 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 081203A (trigger #336489)
(Parsons, et al., GCN Circ. 8595).  The BAT ground-calculated position is
RA, Dec = 233.071, 63.514 deg, which is 
   RA(J2000)  =  15h 32m 16.9s 
   Dec(J2000) = +63d 30' 50.2" 
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 57%.
 
The mask-weighted light curve shows two overlapping peaks.  The first starts
at ~T-70 sec and peaks at ~T+10 sec.  The second peaks at ~T+32 sec and
ends at ~T+400 sec.  T90 (15-350 keV) is 294 +- 71 sec (estimated error
including systematics).
 
The time-averaged spectrum from T-68.9 to T+405.1 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.54 +- 0.06.  The fluence in the 15-150 keV band is 7.7 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+31.12 sec in the 15-150 keV band
is 2.9 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/336489/BA/


GRB_name: GRB081203A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8600
SUBJECT: GRB 081203A: Burst detection from Swift-BAT slew data
DATE:    08/12/03 18:54:02 GMT
FROM:    Antonio Copete at Harvard U  <acopete@head.cfa.harvard.edu>

A. Copete, J. Grindlay (Harvard)
S. Barthelmy, C. Markwardt, N. Gehrels (NASA/GSFC)

We report the detection of a GRB candidate by the BAT Slew Survey  
(BATSS) in the slew that started at 13:52:02 UT. This is 309 sec  
before the trigger time for the GRB that followed (A. M. Parsons et  
al, GCN 8595), which occurs at a different location and should  
hereafter be referred to as GRB 081203B.
The ground-calculated position of GRB 081203A is RA, Dec = 228.789,  
+44.427 deg, which is
  RA (J2000) = 15h 15m 09s
  Dec (J2000) = +44d 25' 36"
with an uncertainty of 3.04 arcmin (90% confidence, including  
systematics). The detection was triggered by simultaneous
independent detections of 11.0 sigma and 5.6 sigma from imaging in the  
15-50 keV and 50-150 keV energy bands, respectively. The burst mask- 
tagged lightcurve shows 2 main peaks, the larger one at T+24sec and  
lasting 2sec as the burst enters the BAT FoV, the second one at T 
+30sec with a duration of 2sec, and it has largely faded as the  
pointing observation that follows begins. The measured T90 = 23.4sec  
and T50 = 8.2sec (15-150keV).

Preliminary spectral analysis from T+24.0 to T+50.4 shows a time- 
averaged spectrum that is best fit by a simple power law with photon  
index of 1.65. The total fluence in the 15-150 keV band is 2.1 x 10^-6  
erg/cm2, and the 1-sec peak flux is 3.5 x 10^-7 erg/cm2/sec.

A follow-up Swift ToO observation has been scheduled to begin at 18:26  
UT, 4.6 hours after the burst.


GRB_name: GRB081203A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8601
SUBJECT: GRB081203A:  Swift/UVOT grism redshift 
DATE:    08/12/03 19:36:15 GMT
FROM:    Wayne Landsman at GSFC/SSAI  <wayne.b.landsman@nasa.gov>

W. Landsman (NASA/GSFC), M.  DePasquale(MSSL),  P. Kuin (MSSL),   P. 
Schady (MSSL),  P. Smith (MSSL), and A.Parsons (NASA/GSFC) report 
on behalf of the  Swift/UVOT team:

The Swift/UVOT obtained a 49s  UV grism spectrum of GRB 081203A starting 
249 s after the  BAT trigger (Parsons et al. GCN.8595).     The  
spectrum covers the wavelength range from 2000-4900 A.      Longward of  
2850 A in the 
quicklook spectrum there is an approximately flat  continuum  of  
2.5e-14 erg s-1 cm-2 A-1 with a strong absorption at 3850 A.  If the 
2850 A cutoff is identified with the Lyman edge, and the 3850 A  
absorption with Lyman alpha, then the redshift of  GRB081203A is 
~2.1.    Analysis is continuing.


GRB_name: GRB081203B
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8602
SUBJECT: GRB 081203B: Naming correction for burst detected in Swift-BAT slew data
DATE:    08/12/03 21:38:46 GMT
FROM:    Antonio Copete at Harvard U  <acopete@head.cfa.harvard.edu>

A. Copete, J. Grindlay (Harvard)
S. Barthelmy, C. Markwardt, N. Gehrels, J. Cummings (NASA/GSFC), D.  
Palmer (LANL)

We hereby correct the naming of the burst first reported by Copete et  
al (GCN 8600), which is unrelated to GRB 081203A (GCNs 8595, 8596,  
8598, 8599 and 8601). Following the standard naming convention for  
same-day bursts to take into account the order of announcement, this  
burst must rather be named GRB 081203B. This name should be used in  
all follow-up circulars referring to this burst.


GRB_name: GRB081203A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8603
SUBJECT: Swift UVOT observations of GRB 081203A
DATE:    08/12/03 22:06:27 GMT
FROM:    Massimiliano de Pasquale at MSSL-UCL  <mdp@mssl.ucl.ac.uk>

  M. De Pasquale (MSSL/UCL) and A. Parsons (GSFC) reports, on the
behalf of the Swift UVOT team:

  Swift UVOT began settled exposures of GRB081203A (trigger 336489,
Parsons et al, GCN circular 8595) 93 s after the burst trigger. A
bright optical transient is detected at the following coordinates:

RA = 15h 32m 07.58s (=233.031580), Dec = +63d 31m 14.9s (=63.520810) 
J2000

  with an uncertainty of 0.5'' (90% confidence level). This position is 
consistent with the XRT refined error circle (Goad et al, GCN circ 8598).

  The source is detected in all filters but um2. Below, we show time of 
observations, the exposure time and the magnitude and 3 sigma upper
limits for this optical afterglow.



       T_start (s)   T_stop (s)   Exp (s)        Mag

  wh       93          242        146.2      14.53 +/- 0.01

  wh      586          605        19.5       13.91 +/- 0.01


  v       636          655        19.5       13.30 +/- 0.03


  b       561          580        19.5       13.53 +/- 0.01


  u       306          555         246       13.07 +/- 0.01

  u       709          728         19.5      13.53 +/- 0.02


  uw1     685          704         19.5      14.82 +/- 0.07


  um2     660          679         19.5          > 17.57

  um2     660         6008        412.6          > 20.1


  uw2     611          630         19.5       17.19 +/- 0.25



  The nondetection in the um2 filter is consistent with the
redshift z=2.1 derived from grism spectra (Landsman et al, GCN
circ 8601). The detection in the uw2 filter is consistent with
this redshift due to the long-wavelength tail of the uw2
filter response.

  The above magnitudes have not been corrected for the Galactic
extinction corresponding to E(B-V) = 0.02 (Schlegel et al 1998)
The photometry is on the UVOT flight system described in Poole
et al (2008, MNRAS, 383,627)

[GCN OPS NOTE(03dec08):  Per author's request, the "A" was added to the burst name.]


GRB_name: GRB081203A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8604
SUBJECT: GRB 081203A: optical observations
DATE:    08/12/03 23:08:16 GMT
FROM:    Igor Volkov at Asro.Inst.Slovak Acad.Sciences  <volkov@ta3.sk>

On 2008 December 03 I have monitored the field of GRB 081203A detected by
SWIFT (Parsons, et al., GCN Circ. 8595) with the 0.5m reflector and
ST-10XME CCD camera of Stara Lesna (Slovak Republic) observatory. My
frames confirm the presence of the afterglow close to coordinates (J2000)
RA = 15h 32m 07.6s, Dec = +63d 31m 14.9s (M. De Pasquale and A. Parsons,
GCN Circ. 8603 ). Observations continued from UT 15:24:45 to UT 16:58:45
in Rc photometric system. The object faided from Rc=15.74+/-0.04 to
Rc=17.20+/-0.06 during this time interval. Several BVIc measurements were
also obtained. GSC 4184 1309 served as a comparison star. The reduction of
the data is in progress and will be available on request.
This study was supported by the SAI scholarship.

Igor Volkov, Astronomical Institute of the Slovak Academy of Sciences, 059
60 Tatranska Lomnica, Slovak Republic; e-mail: volkov@ta3.sk


GRB_name: GRB081203B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8605
SUBJECT: GRB 081203B: Swift-XRT candidate afterglow.
DATE:    08/12/03 23:13:37 GMT
FROM:    Boris Sbarufatti at INAF-IASF-Pa  <sbarufatti@ifc.inaf.it>

B. Sbarufatti, V. La Parola, V. Mangano (INAF-IASF Pa) report on  
behalf of the Swift-XRT team:

Swift began observing the field of the Swift BAT Slew Survey (BATSS)  
GRB 081203B (Copete et al., GCN Circ. 8600, 8602) 16.7 ks after the  
trigger. Using 1419 s of XRT Photon Counting mode data we detect a  
single uncatalogued source inside the BAT error circle. Using the XRT  
data and 2 UVOT images, we find an astrometrically corrected X-ray  
position (using the XRT-UVOT alignment and matching UVOT field  
sources to the USNO-B1 catalogue): RA, Dec =
228.7993, 44.4284 which is equivalent to:

RA (J2000):  15 15 11.83
Dec (J2000): +44 25 42.3

with an uncertainty of 1.8 arcsec (radius, 90% confidence). The  
source lies 27 arcsec from the BAT centroid and has a count rate of  
~5.5e-1 counts/s during this observation.

It is not possible to determine whether this source is fading given  
the current statistics. Further observations are ongoing to clarify  
the nature of this source.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081203B
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8606
SUBJECT: Swift/UVOT detection of GRB081203B
DATE:    08/12/04 00:37:27 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps@mssl.ucl.ac.uk>

P. Schady (MSSL-UCL), F.E. Marshall (NASA/GSFC) and B. Sbarufatti  
(INAF-IASF Pa) report on behalf of the Swift/UVOT team:

The Swift/UVOT began white band observations of the field of the Swift  
BAT Slew Survey (BATSS) GRB 081203B 4.6 hrs after the BAT trigger  
(Copete et al., GCN Circ. 8600, 8602). An uncatalogued, fading source  
is clearly detected at

RA(J2000)  =   15:15:11.67 (228.79863 deg)
DEC(J2000) = +44:25:42.9 (44.42859 deg)

with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence),  
consistent with the UVOT-enhanced XRT position (Sbarufatti et al., GCN  
Circ. 8605).

The magnitudes of the first and last UVOT white band observations are  
reported below:

Filter    T_mid (s)   Exp (s)     Magnitude
white       16746       154        18.29 +/- 0.04
white       22270       441        18.70 +/- 0.03

indicating a decay rate of alpha~1.0. The above magnitudes are not  
corrected for the Galactic extinction corresponding to a reddening of  
E_{B-V} = 0.02 mag (Schlegel et al., 1998, ApJS, 500, 525).  The  
photometry is on the UVOT flight system described in Poole et al.  
(2008, MNRAS, 383,627).


GRB_name: GRB081203B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8607
SUBJECT: GRB 081203B:  SDSS upper limits at the position of the optical afterglow
DATE:    08/12/04 03:32:18 GMT
FROM:    Edo Berger at Harvard  <eberger@cfa.harvard.edu>

E. Berger (Harvard) reports:

"Inspection of SDSS images at the position of the optical afterglow of BAT
Slew Survey GRB 081203B (GCNs #8600,8606) reveals no coincident source to
the following 3-sigma limits:
 u > 22.3 mag
 g > 23.5 mag
 r > 23.4 mag
 i > 22.6 mag
 z > 21.2 mag."


GRB_name: GRB081203B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8608
SUBJECT: GRB 081203B: optical observations
DATE:    08/12/04 04:13:20 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

M. Andreev, A. Sergeev, (Terskol Branch of Institute of Astronomy), Ju. 
Babina (CrAO) A. Pozanenko (IKI) on behalf of larger GRB follow up 
collaboration report:

We observed   the field of GRB 081203B detected by SWIFT in a slew mode 
(Copeteet al, GCN 8600) with the Z-600  telescope of Mt. Terskol 
observatory.  A set of  R-band exposures was taken starting  Dec. 04 (UT) 
01:44. In a combined image of 10x90 s taken at mid time Dec. 04 (UT) 
01:53:45 we detect afterglow (Schady et al, GCN 8606) in coordinate 
(J2000) 15 15 11.66  +44 25 42.7. A preliminary photometry of the 
afterglow at Dec. 04 (UT) 01:53:45 is R=19.8. The photometry is based on 
USNO-A2.0 field stars.

The combine image can be found at 
http://grb.rssi.ru/GRB081203B/grb081203B_Z600_01_53_45.jpg


GRB_name: GRB081203A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8609
SUBJECT: GRB081203A: Swift-XRT refined analysis
DATE:    08/12/04 08:56:13 GMT
FROM:    Valentina La Parola at INAF-IASPA  <laparola@ifc.inaf.it>

V. La Parola, B. Sbarufatti, V. Mangano (INAF-IASF Pa), A. Parsons (GSFC)
report on behalf of the Swift XRT team:

We have analysed the first 3 orbits of Swift-XRT data obtained for
GRB 081203A (trigger #336489, Parsons et al., GCN Circ.8595), that includes
550 s of Windowed Timing (WT) and 15.5 ks of Photon Counting (PC) mode data,
respectively, between 87 s and 16 ks after the trigger.
The UVOT-enhanced XRT position was given by Evans et al. in GCN Circ 8598.

The light-curve can be modelled with a broken power-law, with a steep
decay  alpha_1=4.32  0.16 and a break time at T_b=T0+(150+/-3) s.
After the break the decay flattens to alpha_2=1.175  0.015

The spectrum extracted from the WT data has an exposure of 558 s. It can be
modelled with an absorbed power-law, with Gamma =1.97  0.04 and an
intrinsic
NH = (5.5  0.8)x10^20 cm-2, in excess to the Galactic value of
1.7x10^20 cm-2.
The observed (unabsorbed) 0.3 -10 keV averaged flux over this time
interval is 8.6x10^-10 (10x10^-10) erg cm-2 s-1.

The spectrum extracted from the PC data in the time interval 0.6-16 ks
(with an
exposure time of 4.7 ks) can be modelled with an absorbed power-law, with
Gamma = 2.1  0.08 and an intrinsic column density of NH = (6.0 
1.7)x10^20 cm-2.
The observed (unabsorbed) 0.3 -10 keV averaged flux over this time
interval is 2.8x10^-11 (3.6x10^-11) erg cm-2 s-1.
Uncertainties are given at 90% confidence.

If the light-curve continues to decay with the present rate, the count
rate 24
(36) hours after the burst is estimated to be 0.02 (0.013) count s-1, which
corresponds to an observed flux of 7x10^-13 (4.5x10^-13) erg cm-2 s-1.

The results of the xrt automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00336489.

This is an official product of the Swift-XRT team.


GRB_name: GRB081203B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8610
SUBJECT: Konus-Wind observation of GRB 081203B
DATE:    08/12/04 12:34:28 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P.
Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind
team report:

The long Swift-BATSS GRB 081203B (Copete et al., GCN 8600, 8602)
triggered Konus-Wind at T0=49890.368 s UT (13:51:30.368).

The burst light curve shows a multipeaked structure with a total 
duration of ~80 s.

As observed by Konus-Wind the burst
had a fluence of 5.56(-0.23, +0.24)x10^-5 erg/cm2,
and a 256-ms peak flux measured from T0+10.032 s
of 2.43(-0.40, +0.41)x10^-6 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+64.000 s) can be fitted (in the 20 keV-2 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.165(-0.054, +0.057),
and Ep = 255(-19, +22)  keV (chi2 = 77.8/61 dof).
Fitting by GRB (Band) model yields the same alpha and Ep,
and only an upper limit on the high energy
photon index: beta < -2.59 (chi2 = 77.7/60 dof).

All the quoted errors are at the 90% confidence level.

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.ru/LEA/GRBs/GRB081203_T49890/

[GCN OPS NOTE(04dec08): Per author's request, the authors
were added.]


GRB_name: GRB081203A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8611
SUBJECT: Konus-Wind observation of GRB 081203A
DATE:    08/12/04 16:01:56 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin,
D. Frederiks, P. Oleynik, D. Svinkin, M. Ulanov,
and T. Cline, on behalf of the Konus-Wind team report:

The long GRB 081203A (Parsons et al., GCN 8595, Ukwatta et al., GCN 
8599) was detected by Konus-Wind in the same trigger record as GRB 
081203B (Copete et al., GCN 8600, 8602; Golenetskii et al., GCN 8610) at 
~T0(KW)+260s.
(T0(KW)=49890.368 s UT (13:51:30.368). Correcting for the propagation 
time delay from Wind to Swift of 0.7s, one sees that T0(BAT) corresponds 
to T0(KW)+339.9s).

Since this burst occurred after the end of the time history record 
(=T0(KW)+229s) we do not have the light curve of this GRB with good time 
resolution. Instead we have KW multichannel spectra accumulated until 
T0(KW)+490s (that is until T0(BAT)+150s), which were converted to a 
3-band light curve with a time resolution of 8.192 s.

The burst light curve shows a weak emission starting at ~T0(BAT)-80s 
(=T0(KW)+260s), the main double-peaked pulse starting at ~T0(BAT)-14s 
(=T0(KW)+326s) and the decaying tail seen at least until T0(BAT)+134s 
(=T0(KW)+474s).

As observed by Konus-Wind the burst
had a fluence of 3.05(-0.89, +1.40)x10^-5 erg/cm2
(in the 20 keV - 3 MeV energy range).

The time-integrated spectrum of the burst
(from T0(BAT)-79s to T0(BAT)+134 s) is well fitted
(in the 20 keV-3 MeV range) by a simple power law model
with index 1.54 +/- 0.08 (chi2 = 65.8/69 dof).
Fitting by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields
alpha = -1.33(-0.20, +0.27)
and Ep = 578(-290, +2398)  keV (chi2 = 61.2/68 dof).

The spectrum of the main pulse
(from T0(BAT)-14s to T0(BAT)+52s) is well fitted
(in the 20 keV-3 MeV range) by a power law
with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.29(-0.13, +0.15)
and Ep = 497(-156, +383) keV (chi2 = 66.2/68 dof).

All the quoted errors are at the 90% confidence level.

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.ru/LEA/GRBs/GRB081203A/


GRB_name: GRB081203B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8612
SUBJECT: Swift-XRT observations of GRB 081203B 
DATE:    08/12/04 16:44:11 GMT
FROM:    Boris Sbarufatti at INAF-IASF-Pa  <sbarufatti@ifc.inaf.it>

B. Sbarufatti, V. La Parola, V. Mangano (INAF IASF-Pa) report on  
behalf of the Swift-XRT team.

We report on Swift-XRT observations of GRB 081203B (Copete et al. GCN  
Circ. 8600,8602). We analyzed 3.2 ks of Photon Counting mode data for  
this burst, covering times from T+17 ks to T+ 47 ks. The source  
reported in Sbarufatti et al. (GCN Circ. 8605) and confirmed as the  
afterglow by Schady et al. (GCN Circ. 8606) is fading following a  
power-law decay with index alpha=-1.4 (+0.2/-0.1).

The spectrum for the first data sequence, corresponding to a 1.96 ks  
exposure and covering times from T+17 ks to T+23 ks can be fit by a  
power-law with photon index 2.1+/-0.2, with an absorbing column of  
(7.4+/-0.2)E20 cm**-2, in excess with respect to the galactic value  
of 1.94E20 cm**-2 (Kalberla et al. 2005). The observed (unabsorbed)  
flux is 1.7 (2.2)E-11 erg cm**-2 s**-1. The count-rate-to-flux  
conversion factor is (4.3+/-0.1)E-11.

All quoted errors are at 90% confidence level.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081203A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8613
SUBJECT: VLA Radio upper limit on GRB 081203A
DATE:    08/12/04 18:06:19 GMT
FROM:    Poonam Chandra at U Virginia/NRAO  <pc8s@virginia.edu>

Poonam Chandra (RMC) and Dale A. Frail (NRAO) report on
behalf of the Caltech-NRAO-Carnegie GRB Collaboration:

"We used the Very Large Array to observe the field of view toward
optically bright GRB 081203A (GCN 8595) at a frequency of 8.46 GHz
on 2008 Dec 04.39 UT. The GRB radio afterglow is undetected and
the peak radio flux at the UVOT position (GCN 8595) is 76  54 uJy.

The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."


GRB_name: GRB081204A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8614
SUBJECT: GRB 081204 : a long GRB localized by INTEGRAL 
DATE:    08/12/04 18:12:19 GMT
FROM:    Diego Gotz at CEA  <diego.gotz@cea.fr>

D. Gotz (CEA-Saclay), S.Mereghetti, A.Paizis (IASF-Milano), R. Galis,
V.Beckmann, M. Beck (ISDC, Versoix), and J. Borkowski (CAMK, Torun) on
behalf of the IBAS Localization Team report:

A GRB lasting about 20 s has been detected by IBAS in IBIS/ISGRI data at
16:44:55 UT on December 4th. The refined coordinates (J2000)  are:

RA = 349.7735 [degrees]
DEC= -60.2213 [degrees]

with an uncertainty of 2.3 arcmin (90% c.l.).

A preliminary analysis gives a peak flux in the 20-200 keV range of  
about
0.7 ph/cmq/s (1-s integration time) and a fluence over the same energy
range of about 7x10e-7 erg/cmq.

A plot of the light curve will be posted at

http://ibas.iasf-milano.inaf.it/IBAS_Results.html

This message can be cited.

[GCN OPS NOTE(04dec08): Per author's request, the second "GRB" was added
to the Subject line.]


GRB_name: GRB081203A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8615
SUBJECT: GRB081203A: optical observation
DATE:    08/12/04 18:32:07 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

M. Andreev, A. Sergeev (Terskol Branch of Institute of Astronomy),  Ju. 
Babina  (CrAO), A. Pozanenko (IKI) on behalf of larger GRB follow up 
collaboration report:

We observed   the field of GRB 081203  (Parsons  et al, GCN 8595) with the 
Z-600 telescope of Mt. Terskol observatory  between (UT) Dec.03 14:29-14:38 
(unfiltered exposures of 15 s), Dec.03 14:50 - Dec.04 01:45 (R-band 
exposures of 60  s), and  starting (UT) Dec.04 15:27.

In mid time Dec.04 (UT) 00:50 the afterglow is detected on combined images 
and R=19.5 +/-0.2.  In mid time Dec. 04  (UT) 15:32 we do not detect the 
afterglow up to R=20.6 (3 sigma). The photometry is still preliminary and 
basen on star of SDSS J153155.64+632959.4 (=USNO-B1.0 1534-0214259), 
assuming R=14.69.


GRB_name: GRB081204A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8616
SUBJECT: GRB 081204: Swift XRT afterglow candidate
DATE:    08/12/05 00:15:28 GMT
FROM:    Vanessa Mangano at INAF-IASFPA  <vanessa@ifc.inaf.it>

V. Mangano, B. Sbarufatti, V. La Parola (INAF-IASF PA)
report on behalf the Swift XRT team:

We have analyzed the first orbit data (632 s exposure) of the
Swift ToO observation of the INTEGRAL detected burst GRB 081204
(Gotz, GCN Circ. #8614).
The Swift observation started on 2008 Dec 04 at 19:29 UT,
about 2h 45m after the INTEGRAL trigger.
We detected a single X-ray source within the INTEGRAL error box at
RA, Dec =349.7873, -60.2253 which is equivalent to:

RA (J2000):  23 19 08.96
Dec (J2000): -60 13 31.3

with an uncertainty of 7 arcsec (radius, 90% confidence).
The source lies 29 arcsec from the INTEGRAL position and has
a count rate of ~2.0E-02 counts/s with a 2.6 sigma significance.
At the moment it is not possible to determine whether it is fading,
but the Swift observation is still on going and we are waiting for
more data.

This is an official product of the Swift XRT team.


GRB_name: GRB081203A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8617
SUBJECT: GRB 081203A: Skynet/GORT Detections
DATE:    08/12/05 01:15:13 GMT
FROM:    James Philip West at UNC/Chapel Hill  <jpwest@uncg.edu>

J. P. West, K. McLin, T. Brennan, J. Haislip, D. Reichart, L. Cominsky, T.
Graves, G. Spear, K. Ivarsen, J. A. Crain, A. Foster, R. Holmes, A.
LaCluyze, M. Schubel, J. Styblova, A. Trotter, and E. Weaver report:

Skynet observed the localization of GRB 081203A (Parsons et al., GCN 8595)
with the 14" GORT telescope at Hume Observatory in California beginning 122
seconds after the trigger (101 seconds after notification) in RI.

Only five exposures were taken before morning twilight.  We detect the
afterglow (Parsons et al., GCN 8595) in all five exposures.  Calibrated to
five USNO B1 stars, we find:

mean time
since trigger   exposure        filter          magnitude
(sec)           (sec)

134             20              I               12.79 +/- 0.02
235             40              R               12.60 +/- 0.01
345             40              I               11.58 +/- 0.01
476             80              R               12.51 +/- 0.01
625             80              I               12.02 +/- 0.01

[GCN OPS NOTE(05dec08): Per author's request, the "magnutude time" column label
was changed to "magnitude".]


GRB_name: GRB081203A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8618
SUBJECT: GRB 081203A: Optical observations of Xinglong TNT telescope
DATE:    08/12/05 07:57:42 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

H. Liu, J. Wang, L.P. Xin, Y.L. Qiu, J.Y. Wei, J.Y. Hu, 
J.S. Deng, W.K. Zheng and Y. Urata on behalf of EAFON report:

We have observed GRB081203A (Parsons et al., GCN 8595) 
with Xinglong TNT telescope from Dec.03th,13:57:11(UT),
6.43 hr after the burst to Dec.03,22:19:37.67 (UT).
A series of R band and V band have been obtained.
The optical afterglow was clearly detected in all the images.

Further observations of GRB081203A were also made with 
Xinglong TNT telescope from Dec.04th,21:29:30.409(UT). The 
OT was still marginal detected after combined 11*600s images.

we found the afterglow dacayed from R=19.0 at 7.25 hr to 
R=21.1 at 24.6 hr. The decay slope index is about 1.59, which is
consistent with the index derived from Volkov et al,(GCN 8604).

Further observations are encouraged.

This message may be cited.

For more information about Xinglong GRBs Follow-up 
observations, please visit the website:
http://www.xinglong-naoc.org/grb/


GRB_name: GRB081203A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8619
SUBJECT: GRB081203A: MITSuME optical observation
DATE:    08/12/05 11:04:48 GMT
FROM:    Michitoshi Yoshida at Okayama Astrophysical Obs  <yoshida@oao.nao.ac.jp>

Y. A. Mori, H. Nakajima, T. Shimokawabe, N. Kawai (Tokyo Tech),
D. Kuroda, M. Yoshida, K. Yanagisawa, Y. Shimizu, H. Toda, and
S. Nagayama (OAO, NAOJ) report on behalf of the MITSuME
collaboration:

We performed optical imaging observation of the field of GRB 081203A
(Parsons, et al., GCN Circ. 8595) with the 3-color 50cm MITSuME
Telescopes at Akeno Observatory and Okayama Astrophysical Observatory
from UT 17:50 to UT 20:55, 3.9 hours after the trigger.

In the co-added images of Rc, and g' bands, we detected the optical
afterglow detected with UVOT (Parsons, et al., GCN Circ. 8595).
Photometric calibration was done using the GSC2.3 catalogs.
The results are following:

Akeno:
MID-MJD      MID-UT    EXP-T        g'            Rc
----------------------------------------------------------
54803.753779 18:12:54  1620.0  18.50+/-0.24  18.11+/-0.25
----------------------------------------------------------

Okayama:
MID-MJD      MID-UT    EXP-T        g'            Rc
----------------------------------------------------------
54803.790960 18:58:59  1500.0  18.87+/-0.26  18.36+/-0.19
54803.811830 19:29:03  1500.0  19.18+/-0.25  17.89+/-0.15
54803.833037 19:59:35  1560.0  19.11+/-0.23  18.49+/-0.24
54803.854522 20:30:31  1560.0  19.63+/-0.32  18.91+/-0.19
----------------------------------------------------------


GRB_name: GRB081204A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8620
SUBJECT: GRB 081204: Swift XRT afterglow confirmation
DATE:    08/12/05 14:12:19 GMT
FROM:    Vanessa Mangano at INAF-IASFPA  <vanessa@ifc.inaf.it>

V. Mangano, B. Sbarufatti, V. La Parola (INAF IASF PA),
and W. H. Baumgartner (GSFC/UMBC)
report on behalf the Swift XRT team:

The Swift ToO observation of GRB 081204 started on 2008 Dec 4th
at 19:32 UT consists of 3.6 ks XRT exposure in PC mode.
We confirm the detection of the previously reported afterglow
candidate (Mangano et al., GRC Circ. #8616) at the refined position
RA, Dec = 349.7880, -60.2255 which is equivalent to:

RA (J2000):   23 19 09.13 
Dec (J2000): -60 13 31.7

with an uncertainty of 5.3 arcsec (radius, 90% confidence).
This is 30 arcsec from the INTEGRAL position (Gotz, GCN Circ. #8614).
The source is fading with a power law decay index of about -2,
and will reach a level of about 5.0e-4 counts/s in 24 hours
from the trigger.

The average spectrum accumulated in the time interval from
10 ks to 37 ks after the event was fitted, using Cash
statistics, with an absorbed power law. The best fit photon
index is 2.7  1.5. The spectrum shows evidence of absorption
at the level of (4.4  4.0)e21 cm-2, in excess of the
estimated Galactic value (1.89e+20 cm-2, Kalberla et al. 2005). 
The average observed[unabsorbed] 0.3-10 keV average flux is
about  2.7[8.5]e-13 ergs cm-2 s-1.
The count-rate-to-flux conversion factor is 1.5e-10.

All quoted errors are at 90% confidence level.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081204A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8621
SUBJECT: GRB 081204: Swift/UVOT Upper Limits
DATE:    08/12/05 14:17:38 GMT
FROM:    Peter Curran at MSSL  <pac@mssl.ucl.ac.uk>

P.A. Curran (UCL-MSSL) and W. Baumgartner  (GSFC)
report on behalf of the Swift/UVOT team:


The Swift Ultra-Violet/Optical Telescope (UVOT) began settled ToO 
observations of the  INTEGRAL-IBAS localised  GRB 081204 (Gotz et al., 
GCN 8614) ~ 3 hours after the event. The field was observed with the 
white filter only. No afterglow is detected within the 7" XRT position 
(Mangano et al., GCN 8616) in the co-added image, down to the following 
3-sigma limiting magnitude:

Filter      T_start(s)    Exp(s)     Mag UL (3sig)
-----------------------------------
white      1.01e4        3.4e3      >  22.04
-----------------------------------

There is a DSS detected object approximately 11" south-west of the 
center of the XRT position with an observed white magnitide of ~20.5.

The values quoted above are in the UVOT photometric system (Poole et al. 
2008, MNRAS, 383, 627); they are not corrected for the expected Galactic 
extinction along the line of sight which corresponds to a reddening of 
E(B-V)=0.027 mag (Schlegel et al. 1998).

[GCN OPS NOTE(05dec08): Per author's request, the typo for T_start
in the table was changed from 1.01e5 to 1.01e4.]


GRB_name: GRB081204B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8622
SUBJECT: GRB 081204B: Fermi GBM detection
DATE:    08/12/05 15:48:57 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs@mpe.mpg.de>

E. Bissaldi and A. von Kienlin (MPE)
report on behalf of the Fermi GBM Team: 

"At 12:24:25.79 UT on 4 December 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 081204B (trigger 250086266 / 081204517).
The on-ground calculated location, using the GBM trigger
data, is RA = 181.4, DEC = +32.1 (J2000 degrees,
equivalent to 12h 06m, 32d 06'), with an uncertainty
of 7.3 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).

The angle from the Fermi LAT boresight is 46 degrees.

This short GRB consists of a single pulse
with a duration (T90) of about 320 ms (8-1000 keV).
The time-averaged spectrum from T0-0.077 s to T0+0.115 s is
best fit by a simple power law function with
index -1.18 +/- 0.05 (chi squared 439 for 477 d.o.f.).
The event fluence (8-1000 keV) in this time interval is
(4.88 +/- 0.13)E-07 erg/cm^2. The peak photon flux
on the 64 ms timescale measured starting from T0-0.077 s
in the 8-1000 keV band is 16.3 +/- 0.6 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081203A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8623
SUBJECT: GRB081203A: Radio upper limit at 15 GHz
DATE:    08/12/05 17:33:51 GMT
FROM:    Guy Pooley at MRAO, Cambridge, UK  <ggp1@cam.ac.uk>

Guy Pooley (MRAO/Cavendish Astrophysics, University of Cambridge) reports:

We used the AMI large array (the rebuilt/upgraded Ryle Telescope)
in the band 14 - 17 GHz to observe the field of the optically 
bright GRB 081203A (GCN 8595). There was no detection of the afterglow on 
either of two observations. The measured flux densities at the optical 
position are:

2008 Nov 04.26   116 +- 300 microJy
2008 Nov 05.24    80 +- 200 microJy 

(cf Chandra & Frail, GCN 8613, for an upper limit at 8.46 GHz)


GRB_name: GRB081204A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8624
SUBJECT: GRB 081204: Magellan observations
DATE:    08/12/05 19:39:37 GMT
FROM:    Edo Berger at Harvard  <eberger@cfa.harvard.edu>

E. Berger and A. Rest (Harvard) report:

"We observed the position of GRB 081204 (GCN 8614) with the LDSS3
instrument on the Magellan/Clay telescope.  A total of 30 sec were
obtained in r- and i-band on 2008 Dec 5.067 UT (8.86 hour after the
burst).  Within the XRT error circle (GCN 8620) we detect a single faint
source with r=23.5+/-0.3 mag and i=23.0+/-0.2 mag located at:
 RA  = 23:19:09.41
 DEC = -60:13:31.4  (J2000)
with an uncertainty of about 0.3" in each coordinate (astrometry relative
to USNO-B).  At the moment we have no information on whether the source is
variable."


GRB_name: GRB081203B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8625
SUBJECT: Radio detection of GRB 081203B with the VLA
DATE:    08/12/05 21:12:08 GMT
FROM:    Poonam Chandra at U Virginia/NRAO  <pc8s@virginia.edu>

Poonam Chandra (RMC) and Dale A. Frail (NRAO) report on
behalf of the Caltech-NRAO-Carnegie GRB Collaboration:

"We used the Very Large Array to observe the field of view toward
optically bright GRB 081203B (GCN 8600) at a frequency of 8.46 GHz
on 2008 Dec 05.70 UT. We detect a radio afterglow at the optical
afterglow position quoted by  Andreev et al (GCN 8608). The peak radio
flux at this position is 160 +/- 41 uJy.

The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."


GRB_name: GRB081203B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8626
SUBJECT: GRB081203B: optical observations
DATE:    08/12/05 21:53:05 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

M. Andreev, A. Sergeev, (Terskol Branch of Institute of Astronomy), Ju. 
Babina (CrAO) A. Pozanenko (IKI) on behalf of larger GRB follow up 
collaboration report:

We are continuing observation  (Andreev et al, GCN 8608) of  the GRB081203B 
(Copeteet et al, GCN 8600) with the Z-600  telescope of Mt. Terskol 
observatory.  A set of  R-band exposures was taken between Dec.05  (UT) 
02:33-03:19. In a combined image of 30x90 s   at mid time Dec. 05 (UT) 02:56 
we still detect afterglow of the GRB081203B (Schady et al, GCN 8606). A 
photometry of the afterglow   is 20.9 +/- 0.3. The photometry is based on 
USNO-A2.0   star 1275_08617401   (RA 15 15 10.21 Dec:  +44 26 01.4) assuming 
R=17.1. 


GRB_name: GRB081204A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8627
SUBJECT: GRB 081204: GROND Observations
DATE:    08/12/06 11:45:59 GMT
FROM:    Adria C. Updike at Clemson U  <aupdike@clemson.edu>

A. Updike (Clemson University), C. Clemens, and J. Greiner (both MPE
Garching) report on behalf of the GROND team:

We observed the field of GRB 081204 (INTEGRAL trigger #5385; D. Gotz et
al., GCN #8614) for two epochs simultaneously in g'r'i'z'JHK with GROND
(Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m ESO/MPI
telescope at La Silla Observatory (Chile).

Observations began at 00:30 UT on Dec 5, 2008, 7.75 hr after the GRB
trigger, and consisted of 2.4 hours of exposures.  The second epoch began
at 00:31 UT on Dec 6, 31.75 hr after the trigger, and consisted of 1.3
hours of exposures. Observations were performed under favorable sky
conditions.

We detect two sources within the refined 5.3'' Swift-XRT error circle
reported by V. Mangano et al. (GCN #8620), at the astrometrically
corrected positions:

RA (J2000) 23h 19m 09.10s
Dec (J2000) -60d 13' 29.7"

and

RA (J2000) 23h 19m 09.37s
Dec (J2000) -60d 13' 31.2"

The second candidate agrees with the position reported by Berger & Rest
(GCN #8624).

We detect no evidence of fading in either source between the two epochs.
Therefore, we suggest that neither of the sources are the afterglow of
GRB 081204.

Our upper limits from the first epoch in g'r'i'z'JHK are as follows:

g' > 24.2
r' > 24.3
i' > 23.6
z' > 22.9
J  > 20.7
H  > 19.4
K  > 18.3

The given magnitudes are calibrated against GROND zeropoints as well as
2MASS field stars.


GRB_name: GRB081128A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8628
SUBJECT: GRB 081128: Optical afterglow observations
DATE:    08/12/06 12:11:55 GMT
FROM:    Shashi Bhushan Pandey at ARIES, INDIA  <shashi@aries.ernet.in>

Brajesh Kumar, S. B. Pandey and Rupak Roy (ARIES, NainiTal, India, on
behalf of larger Indian GRB collaboration)

GRB 081128, localized by Swift (Margutti et al. GCN 8571), was observed
with 1.04m telescope at NainiTal starting ~ 2.5 hours after the burst
in R_c filter.

Photometry of the co-added R_c frames (300 sec x 5) does not detect the
optical afterglow candidate (Wang et al. GCN 8572) down to a limiting
magnitude of ~ 20 mag in comparison to nearby USNO stars.

This message may be cited.


GRB_name: GRB081203A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8629
SUBJECT: GRB081203A: Optical observations at Ishigaki
DATE:    08/12/06 13:25:53 GMT
FROM:    Mizuki Isogai at NAOJ  <mizuki.isogai@nao.ac.jp>

M. Isogai (IAO, NAOJ) and N. Kawai (Tokyo Tech) report with support 
of MITuME collaboration:

We observed the field of GRB 081203A(Parsons, et al., GCN Circ. 8595) 
with the optical 3-color imager attached to the 105cm Murikabushi 
Telescope at Ishigakizima Astronomical Observatory in Japan from 
UT 19:52, 5.9 hours after the trigger.

In the co-added images of Ic, Rc, and g' bands, we detected a fading
point source and measured its magnitude. Photometric calibration was 
performed using the GSC2.3 catalogs. 
The results are following:

MID-MJD      MID-UT    EXP-T      g'             Rc           Ic
----------------------------------------------------------------------
54803.837345 20:05:46  720.0                              18.50+/-0.09
54803.837345 20:05:46  900.0  19.43+/-0.11  18.76+/-0.06
54803.847273 20:20:04  720.0  19.39+/-0.11  
54803.848363 20:21:38  900.0                18.83+/-0.06  18.49+/-0.08
54803.859451 20:37:36  900.0  19.57+/-0.11  18.96+/-0.06  18.67+/-0.09
54803.870356 20:53:18  900.0  19.77+/-0.11  18.94+/-0.07  18.72+/-0.10
54803.881257 21:09:00  900.0  19.71+/-0.12  19.04+/-0.07  18.71+/-0.10


GRB_name: GRB081128A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8630
SUBJECT: GRB 081128: optical observation in CrAO
DATE:    08/12/06 15:33:01 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

V. Rumyantsev, D. Shakhovkoy, S. Sergeev (CrAO), M.Andreev (Terskol Branch 
of Institute of Astronomy), A. Pozanenko (IKI) on behalf of larger GRB 
follow up collaboration report:

We observed the error box of Swift GRB 081128 (Margutti  et al, GCN 8571) in 
R band on Nov. 28 between (UT) 17:53:23 - 19:05:55 with AZT-11 telescope of 
CrAO. Inside the refined XRT error box (Evans et al. GCN 8573) we detect the 
source reported as possible afterglow (Wang et al, GCN 8572; Lin et al, GCN 
8575; Andreev et al, GCN 8576; Guidorzi et al, GCN 8577).  The coordinates 
of the source are   RA(J2000):  01 23 13.03 Dec(J2000): +38 07 37.7 with 
uncertainty of 0.5". A photometry based on  USNO-B1.0 star 1281-0027628 
(01:23:11.75 +38:07:43.6) R2=17.91 is following:

T0+    Filter,  Exp.,   mag.        UL
(h)             (s)                (3 sigma)

1.207  R        23x180  21.5 +/-0.2  22.4

Taking above photometry and photometry reported earlier  (Lin et al, GCN 
8575; Andreev et al, GCN 8576; Guidorzi et al, GCN 8577) we confirm the 
fading nature of the source. We also detected the source  (Guidorzi et al, 
GCN 8577) which is ~4"  South of OT.

A combined image can be found at 
http://grb.rssi.ru/GRB081128/GRB081128_AZT11_R_18_31_09.gif 


GRB_name: GRB081203B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8631
SUBJECT: GRB 081203B: Gemini observations
DATE:    08/12/07 12:10:52 GMT
FROM:    Daniel Perley at U.C. Berkeley  <dperley@astro.berkeley.edu>

D. A. Perley and J. S. Bloom (UC Berkeley) report:

We triggered Gemini-N (GMOS) observations of BATSS GRB 081203B (Copete 
et al., GCN 8600, 8602) starting at 15:04 UT 2008-12-06 through very 
high airmass but under good conditions.  In our acquisition image we 
identify a source at the position of the optical afterglow (Schady et 
al., GCN 8606).  Photometry, calibrated to SDSS, is:

r = 21.90 +/- 0.06   (t = 3.05 days)

Two spectroscopic integrations of 1200s each were acquired using the 
R150 grating.  Preliminary inspection of the frames reveals no obvious 
line features between 5200-9000 A.  Further analysis is continuing.


GRB_name: GRB081203A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8632
SUBJECT: GRB081203A: Ashra-1 observation of early optical and VHE-neutrino  emission
DATE:    08/12/07 16:54:46 GMT
FROM:    Makoto Sasaki at ICRR/U.Tokyo  <sasakim@icrr.u-tokyo.ac.jp>

Y.Aita, Y.Asaoka, T.Chonan, Y.Higashi, K.Noda, and M.Sasaki
(ICRR,Univ.Tokyo), Y.Morimoto, S.Ogawa (Toho Univ.), J.Learned
(Univ.Hawaii Manoa), R.Fox (Univ.Hawaii Hilo) report on behalf of the
Ashra-1 collaboration:

We have searched for optical and VHE-neutrino emission in the field of
GRB081203A (A. M. Persons et al., GCN Circ. 8595) around the
BAT-triggered GRB time (T0) with one of the light collector units in
the Ashra-1 detector (http://www.icrr.u-tokyo.ac.jp/~ashra) on Mauna
Loa on Hawaii Island (latitude = 19.5412 deg. N, longitude =155.5676
deg. W, altitude =3330m).

The Ashra-1 light collector unit has the achieved resolution of a few
arcmin, viewing 42 degree circle region of which center is located at
Alt = 11.7 deg, Azi = 22.1 deg. The sensitive region of wavelength is
similar with the B-band.

We quickly analyzed 83 images covering the field of GRB081203A every
7.2s with 6s exposure time respectively during the observation between
T0-300s and T0+300s. We detected no new optical object within the PSF
resolution around the GRB081203A determined by Swift-UVOT (M. De
Pasquale et al.,GCN Circ. 8603).

As a result of our preliminary analysis, the following 3-sigma
limiting magnitudes are derived:
----------------------------------------------------------------------
Starting&Ending Exp.Time,  3-sigma Limit. Mag.
----------------------------------------------------------------------
-297.7   -291.7                    11.9
-290.7   -284.7                    11.9
   .        .                       .
   .        .                       .
 -1.7      4.3                    11.9
  5.3     11.3                    11.8
   .        .                       .
   .        .                       .
 287.3    293.3                    11.9
 294.3    300.3                    11.9
----------------------------------------------------------------------
The limiting magnitudes were estimated in comparison with stars in
Tycho-2 Catalog to be distributed between 11.7 and 12.0 as above
partly listed.

Adding that we have searched for VHE-neutrino emission with the
primary neutrino energy above 10^16eV by detecting Cherenkov lights
from tau-decay induced air-showers. VHE neutrinos are expected to be
produced at the GRB behind Mauna Kea and converted into tau leptons in
the mountain rock. The GRB position was passed through our triggering
region viewing onto the face of Mauna Kea from 11:07UT to 11:49UT
(2.83 hours to 2.13 hours before the GRB). We have no signal come out
of the mountain. The limiting flux is now under analysis.

Figures of limiting optical magnitudes vs time comparing with other
measurements and more details on the VHE neutrino observation can be
found at: http://www.icrr.u-tokyo.ac.jp/~ashra/GRB081203A.

This message may be cited.

////////////////////////////////////////////////////////////////
SASAKI Makoto
ICRR, University of Tokyo
5-1-5 Kashiwa-no-ha Kashiwa 277-8582
tel/fax +81-4-7136-3143
////////////////////////////////////////////////////////////////


GRB_name: GRB081008A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8633
SUBJECT: Radio observation of GRB 081008 with ATCA
DATE:    08/12/08 01:46:28 GMT
FROM:    Aquib Moin at CIRA/ATNF  <aquib.moin@postgrad.curtin.edu.au>

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the SWIFT/UVOT refined position of the GRB 081008 optical
afterglow (GCN 8348) at 4.800 and 4.928 GHz with the Australia Telescope
Compact Array (ATCA) between 01:15:05 UT, November 24, 2008 and 20:35:30
UT, November 25, 2008.

We did not detect a radio source at the optical afterglow position of
the GRB 081008 (GCN 8348). The data at 4.800 and 4.928 GHz were merged
and the radio flux density at the afterglow position found out to be
-0.151 +/- 0.156 mJy/beam (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See the 4.800 & 4.928 GHz combined image at:

http://cira.ivec.org/dokuwiki/doku.php/grb/grb081008_field_image 


GRB_name: GRB081029A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8634
SUBJECT: Radio observation of GRB 081029 with ATCA
DATE:    08/12/08 01:59:11 GMT
FROM:    Aquib Moin at CIRA/ATNF  <aquib.moin@postgrad.curtin.edu.au>

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the SWIFT/UVOT refined position of the GRB 081029 optical
afterglow (GCN 8450) at 4.800 and 4.928 GHz with the Australia Telescope
Compact Array (ATCA) between 01:15:05 UT, November 24, 2008 and 20:35:30
UT November 25, 2008.

We did not detect a radio source at the optical afterglow position of
the GRB 081029 (GCN 8450). The data at 4.800 and 4.928 GHz were merged
and the radio flux density at the afterglow position found out to be
-0.168 +/- 0.219 mJy/beam (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See the 4.800 & 4.928 GHz combined image at:

http://cira.ivec.org/dokuwiki/doku.php/grb/grb081029_field_image 


GRB_name: GRB081104A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8635
SUBJECT: Radio observation of GRB 081104 with ATCA
DATE:    08/12/08 04:02:10 GMT
FROM:    Aquib Moin at CIRA/ATNF  <aquib.moin@postgrad.curtin.edu.au>

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the GROND position of the GRB 081104 optical afterglow (GCN
8482) at 4.800 and 4.928 GHz with the Australia Telescope Compact Array
(ATCA) between 01:15:05 UT, November 24, 2008 and 20:35:30 UT November
25, 2008.

We did not detect a radio source at the optical afterglow position of
the GRB 081104 (GCN 8482). The data at 4.800 and 4.928 GHz were merged
and the radio flux density at the afterglow position found out to be
-0.142 +/- 0.152 mJy/beam (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See the 4.800 & 4.928 GHz combined image at:

http://cira.ivec.org/dokuwiki/doku.php/grb/grb081104_field_image 


GRB_name: GRB081109A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8636
SUBJECT: Radio observation of GRB 081109 with ATCA
DATE:    08/12/08 04:16:50 GMT
FROM:    Aquib Moin at CIRA/ATNF  <aquib.moin@postgrad.curtin.edu.au>

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the REM position of the GRB 081109 optical afterglow (GCN
8501) at 4.800 and 4.928 GHz with the Australia Telescope Compact Array
(ATCA) between 01:15:05 UT, November 24, 2008 and 20:35:30 UT, November
25, 2008.

We did not detect a radio source at the optical afterglow position of
the GRB 081109 (GCN 8501). The data at 4.800 and 4.928 GHz were merged
and the radio flux density at the afterglow position found out to be 25
+/- 92 uJy/beam (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See the 4.800 & 4.928 GHz combined image at:

http://cira.ivec.org/dokuwiki/doku.php/grb/grb081109_field_image 


GRB_name: GRB081203B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8637
SUBJECT: GRB 081203B: Additional Gemini imaging
DATE:    08/12/08 05:07:27 GMT
FROM:    Daniel Perley at U.C. Berkeley  <dperley@astro.berkeley.edu>

D. A. Perley (UC Berkeley) reports on behalf of a larger collaboration:

During morning twilight on 2008-12-07 UT (starting at 15:40) we 
undertook additional imaging of the optical transient associated with 
GRB 081203B, using GMOS on Gemini-North.  We report the following 
magnitudes:

g = 22.67 +/- 0.11 (t = 4.076 day)
r = 22.41 +/- 0.10 (t = 4.079 day)
i = 22.16 +/- 0.20 (t = 4.082 day)

Assuming a burst time of 13:52:02 UT (GCN 8600).

The SED is well-fit by a power-law with beta = 1.0 +/- 0.3.  The 
power-law index of the light curve compared with our r-band measurement 
the previous night (GCN 8631) is alpha = 1.6 +/- 0.3.  Both values are 
consistent with typical late-time GRB afterglow behavior.

We thank the Gemini staff for conducting these observations, which were 
carried out under program GN-2008B-Q-6.


GRB_name: GRB081203B
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8638
SUBJECT: GRB 081203B: Suzaku WAM observation of the prompt emission
DATE:    08/12/08 08:18:54 GMT
FROM:    Masanori Ohno at ISAS/JAXA  <ohno@astro.isas.jaxa.jp>

Y.Terada, M. Tashiro, Y. Urata, A. Endo, K. Onda, 
N. Kodaka, K. Morigami, T. Sugasahara, W. Iwakiri (Saitama U.),
S. Sugita, K. Yamaoka (Aoyama Gakuin U.),  
M. Ohno, M. Kokubun, M. Suzuki, T. Takahashi (ISAS/JAXA), 
Y.E. Nakagawa, T. Tamagawa (RIKEN), 
T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), 
T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira, Y. Hanabata (Hiroshima U.),
E. Sonoda, M. Yamauchi, H. Tanaka, R. Hara, N. Ohmori, K. Kono, H.Hayashi, 
(Univ. of Miyazaki),S. Hong (Nihon U.), 
on behalf of the Suzaku WAM team, report:

The long GRB 081203B (Swift/BAT Slew Survey, Copete et al., GCN Circ. 8600, 
8602) triggered the Suzaku Wide-band  All-sky Monitor (WAM) which covers 
an energy range of 50 keV - 5 MeV at 2008-12-03 13:51:31.94713598 UT (=T0). 
The observed light curve shows a multi-peaked structure starting at T0-0.5s, 
ending at T0+64s with a duration (T90) of about 45 seconds. The fluence in
100 - 1000 keV was 2.9 x 10^-5 erg/cm^2. The 1-s peak flux measured from 
T0+11.25s was 2.9 photons/cm^2/s in the same energy range.
Preliminary result shows that the time-averaged spectrum from
T0-3s to T0+64s is well fitted by a power-law with exponential cutoff model:
  dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
  alpha       1.2 -0.2 +0.3 and
  Epeak       304 -20 +22 keV (chi^2/d.o.f. = 50.6/28).
All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.
The light curves for this burst are available at:

 http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html


GRB_name: GRB081128A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8639
SUBJECT: GRB 081128: afterglow observations
DATE:    08/12/08 08:35:39 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@astro.ku.dk>

D. Malesani, J.P.U. Fynbo, G. Leloudas (DARK/NBI), H. Pedersen (NBI), P. 
Jakobsson (Univ. Iceland), S.-M. Niemi, H. Uthas, and C. Villforth 
(NOT), report on behalf of a larger collaboration:

We observed the field of GRB 081128 (Margutti et al., GCN 8571) with the 
Nordic Optical Telescope equipped with ALFOSC. Observations were carried 
out on two epochs, first on 2008 Nov 28.962 (0.24 days after the GRB) in 
the V, R and i bands and then on Dec 7.827 (9.10 days after the GRB) in 
the R band. In the first epoch we detect the afterglow candidate 
reported by Wang et al. (GCN 8572) in all filters. We estimate R=22.3 +- 
0.1 assuming R=17.91 for the USNO star at RA = 01:23:11.73, Dec = 
+38:07:43.58 (consistent with the calibration of Guidorzi et al., GCN 
8577; C. Guidorzi, priv. comm.). In the second epoch, the afterglow 
candidate remains undetected to a limit R > 23.5, and we hence confirm 
that this source is the GRB afterglow. We note that the V-band detection 
sets a limit on the GRB redshift, z <~ 5.

We also detect in both epochs a second object at the border of the XRT 
error circle (RA = 01:23:12.98, Dec = +38:07:38.4), which is likely the 
one reported by Guidorzi et al. (GCN 8577), with a magnitude R = 22.7. 
The angular separation from the afterglow is 1.2".


GRB_name: GRB081206A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8640
SUBJECT: GRB 081206: Fermi GBM detection
DATE:    08/12/08 16:10:09 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE) 
reports on behalf of the Fermi GBM Team: 

"At 06:35:53.02 UT on 06 December 2008, the Fermi Gamma-Ray Burst Monitor 
triggered and located GRB 081206 (trigger 250238154 / 081206275).

The on-ground calculated location, using the GBM trigger 
data, is RA = 120.1, DEC = 32.7  (J2000 degrees, 
equivalent to 08h 00m, 32d 42'), with an uncertainty 
of 5.2 degrees (radius, 1-sigma containment, 
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
 
The angle from the Fermi LAT boresight is 102 degrees.

The GBM light curve consists of a single peak
with a duration (T90) of about 24 s (8-1000 keV). 
The time-averaged spectrum from T0-6.144 s to T0+15.360 s is 
well fit by a power law function with an exponential
high energy cutoff.  The power law index is -0.11 +/- 0.24 and
the cutoff energy, parameterized as Epeak, is 180 +/- 23 keV 
(chi squared 245 for 236 d.o.f.).
The event fluence (8-1000 keV) in this time interval is 
(4.0 +/- 0.6)E-06 erg/cm^2. The 1-sec photon flux measured 
starting from T0+3.072 s in the 8-1000 keV band 
is 2.4 +/- 0.3 ph/s/cm^2.

A Band function fits the spectrum equally well 
(chi squared 242 for 235 d.o.f.) with Epeak= 151 +/- 29 keV, 
alpha = 0.13 +/- 0.37 and beta = -2.2 +/- 0.4. 

The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081206B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8641
SUBJECT: GRB 081206B: Fermi GBM detection
DATE:    08/12/08 16:52:41 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE)
reports on behalf of the Fermi GBM Team: 

"At 14:29:30.69  UT on 06 December 2008, the Fermi Gamma-ray Burst Monitor
(GBM) triggered and located GRB 081206B (trigger 250266571 / 081206604). 
The on-ground calculated location, using the Fermi GBM trigger data, 
is RA = 346.2, Dec = -33.1 (J2000 degrees, equivalent to 
J2000 23h 05m, -33d 06'), with a statistical uncertainty of 13.2 degrees 
(radius, 1-sigma containment, statistical only; there is additionally 
a systematic error which is currently estimated to be 2 to 3 degrees). 

The angle from the Fermi LAT boresight is 82 degrees. 

The GBM light curve shows a single peak with a duration of about 10 s. Since

the source is weak, the time-averaged spectrum is poorly constrained."


GRB_name: GRB081118A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8642
SUBJECT: Radio observation of GRB 081118 with ATCA
DATE:    08/12/09 02:03:37 GMT
FROM:    Aquib Moin at CIRA/ATNF  <aquib.moin@postgrad.curtin.edu.au>

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the VLT position of the GRB 081118 optical afterglow (GCN
8528) at 4.800 and 4.928 GHz with the Australia Telescope Compact Array
(ATCA) between 01:15:05 UT, November 24, 2008 and 20:35:30 UT, November
25, 2008.

We did not detect a radio source at the optical afterglow position of
the GRB 081118 (GCN 8528). The data at 4.800 and 4.928 GHz were merged
and the radio flux density at the afterglow position found out to be -89
+/- 5.6 uJy/beam (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See the 4.800 & 4.928 GHz combined image at:

http://cira.ivec.org/dokuwiki/doku.php/grb/grb081118_field_image 


GRB_name: GRB081121A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8643
SUBJECT: Radio observation of GRB 081121 with ATCA
DATE:    08/12/09 02:14:46 GMT
FROM:    Aquib Moin at CIRA/ATNF  <aquib.moin@postgrad.curtin.edu.au>

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the SWIFT-UVOT refined position of the GRB 081121 optical
afterglow (GCN 8544) at 4.800 and 4.928 GHz with the Australia Telescope
Compact Array (ATCA) between 01:15:05 UT, November 24, 2008 and 20:35:30
UT, November 25, 2008.

We did not detect a radio source at the optical afterglow position of
the GRB 081121 (GCN 8544). The data at 4.800 and 4.928 GHz were merged
and the radio flux density at the afterglow position found out to be
0.106 +/- 0.208 mJy/beam (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See the 4.800 & 4.928 GHz combined image at:

http://cira.ivec.org/dokuwiki/doku.php/grb/grb081121_field_image 


GRB_name: GRB081206C
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8644
SUBJECT: GRB 081206C: Fermi GBM detection
DATE:    08/12/09 21:03:11 GMT
FROM:    Sylvain Guiriec at UAH  <sylvain.guiriec@lpta.in2p3.fr>

S. Guiriec (UAH) and A.J. van der Horst (NASA/MSFC/ORAU)
report on behalf of the Fermi GBM Team:

"At 23:41:50.47 UT on 6 December 2008, the Fermi Gamma-Ray Burst Monitor
 triggered and located GRB 081206C (trigger 250299711 / 081206987).

The on-ground calculated location, using the GBM trigger data, is
 RA = 41.12, DEC = -14.42 (J2000 degrees, equivalent to +2h44m, -14d25'),
with an uncertainty of 7.7 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic error which is
currently estimated to be 2 to 3 degrees).

The angle from the Fermi LAT boresight is 71 degrees.

The GBM light curve shows a main pulse of ~20 seconds starting at ~T0-11s.
There is additional weak emission up to T0+83s.

The time-averaged spectrum from T0-9s to T0+11s is adequately fit by a
simple power-law function with index -1.35 +/- 0.04
(chi squared 505 for 481 d.o.f.).
The fluence (50-300 keV) in this time interval is
(1.19 +/- 0.04)E-6 erg/cm^2.
The 1-sec peak photon flux measured starting from T0-1s in the 50-300 keV
 band is 0.76 +/- 0.04 ph/s-cm^2.

The spectral and timing analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081203A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8645
SUBJECT: GRB 081203A: optical observations
DATE:    08/12/10 02:07:24 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

V. Rumyantsev, K. Antonyuk (CrAO), M. Andreev(Terskol Branch of Institute 
of Astronomy), A. Pozanenko (IKI) on behalf of larger GRB follow up 
collaboration report:

We observed   the field of GRB 081203  (Parsons  et al, GCN 8595) with the 
AZT-11 telescope of CrAO observatory  starting  Dec. 03 (UT) 15:44:29 
under good weather conditions and seeing of about ~2 arcsec. Several 
exposures were obtained in VRI bands up to 17:13:56 and then between
Dec. 04 (UT) 01:19:13 - 02:47:51.

Coordinates of the afterglow are RA(J2000)= 15:32:07.58 Dec(J2000)= 
+63:31:14.8 with uncertainty of 0.2 arcsec which is compatible with the 
coordinates of the afterglow (Parsons  et al, GCN 8595).

Preliminary photometry based on SDSS star J153200.06+633229.9 
(RA(J2000)=15:32:00.01 Dec(J2000)=+63:32:30.4) assuming V=17.28   R=16.85 
I=16.46 is following

T0+  Filter Exp.  mag.
s           s

  6528 V     180   16.84 +/-0.02
  6712 R     180   16.63 +/-0.02
  6896 I     180   16.22 +/-0.02
11524 V     180   17.68 +/-0.05
11708 R     180   17.53 +/-0.03
11892 I     180   17.15 +/-0.04
41196 R   3x180   20.27 +/-0.15
46144 R   3x180   20.20 +/-0.14

While light curves in a time interval 6500 - 12000 s after burst onset in 
R and I bands look similar with a power law decay index of about 0.66, the 
power law decay index in V-band is ~0.59 and one can suggest a spectral 
variability of the afterglow. Also we observed steep decay between 12000 - 
46000 s with a power law index of about 1.9.


GRB_name: GRB081209A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8646
SUBJECT: IPN triangulation of short hard GRB 081209 
DATE:    08/12/10 16:36:58 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and K. 
Hurley on behalf of the Konus-Wind team,

J. Cummings, S. Barthelmy, N. Gehrels, and H. Krimm, on behalf of
the Swift-BAT team,

M. Marisaldi, F. Fuschino, E. Del Monte, Y. Evangelista, I. Lapshov, M. 
Rapisarda, and A. Giuliani, on behalf of the AGILE Team,
report:

AGILE-MCAL, Swift-BAT, and Konus-Wind observed the short-duration hard 
spectrum GRB 081209 at about 23:31:56 UT (corresponds to the Fermi/GBM 
trigger 250558317). The burst was outside the coded field of view of the 
BAT and SuperAGILE. The burst light curve shows a single peak with a 
duration of ~0.2 sec.

Triangulation gives an annulus centered at RA(2000)=77.269 (05h 09m 05s) 
  Dec(2000)=+17.346 (+17d 20' 47"), whose radius is 48.435 +/- 0.181 deg 
(3sigma).  This intersects the GBM error circle (the Fermi-GBM ground 
position is RA(2000), Dec(2000) = 88.980d (+05h 55m 55s), +71.450d (+71d 
27' 00")) assuming its 3sigma uncertainty of 11.8 deg (7.8deg stat + 
3deg syst)) to form a long 3sigma error box whose corners are at
-------------------------------------------------
        RA(2000)                 Dec(2000)
-------------------------------------------------
  104.995 (06h 59m 59s)   +61.438 (+61d 26' 16")
  105.760 (07h 03m 02s)   +61.616 (+61d 36' 58")
   62.128 (04h 08m 31s)   +64.879 (+64d 52' 43")
   62.813 (04h 11m 15s)   +64.597 (+64d 35' 47") 
--------------------------------------------------

This error box may be improved.

Preliminary analysis of the Konus-Wind data yields
a burst fluence of ~2x10^-6 erg/cm2 (in the 20 keV - 3 MeV range),
and an Epeak of the time-integrated spectrum of ~1 MeV.

Detailed spectral parameters will be reported later.

The K-W light curve of this GRB and IPN triangulation map is
available at http://www.ioffe.ru/LEA/GRBs/GRB081209_T84720/


GRB_name: GRB081209A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8647
SUBJECT: Konus-Wind observation of GRB 081209
DATE:    08/12/10 17:49:19 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P.
Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind
team, report:

The short hard GRB 081209 (Golenetskii et al., GCN 8646; Fermi GBM 
trigger 250558317) triggered Konus-Wind at T0=84720.033 s UT (23:32:00.033).

As observed by Konus-Wind the burst
had a fluence of 2.39(-0.52, +0.58)x10^-6 erg/cm2,
and a 16-ms peak flux measured from T0-0.012 s
of 2.68(-0.83, +0.87)x10^-5 erg/cm2/s
(both in the 20 keV - 3 MeV energy range).

The spectrum accumulated from T0 to T0+0.128 s is well fitted (in the 20 
keV - 3 MeV range) by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.33(-0.31, +0.41),
and Ep = 961(-257, +432) keV (chi2 = 11.2/17 dof).
Fitting by GRB (Band) model yields the same alpha and Ep,
and only an upper limit on the high energy
photon index: beta < -1.7 (chi2 = 11.2/16 dof).

All the quoted errors are at the 90% confidence level.


GRB_name: GRB081210A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8648
SUBJECT: GRB 081210: Swift detection of a burst with optical afterglow
DATE:    08/12/10 20:37:36 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

H. A. Krimm (CRESST/GSFC/USRA), A. P. Beardmore (U Leicester),
P. J. Brown (PSU), D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC),
P. A. Evans (U Leicester), C. Guidorzi (UniFE),
S. T. Holland (CRESST/USRA/GSFC), S. D. Hunsberger (PSU),
S. Immler (CRESST/GSFC/UMD), J. A. Kennea (PSU), W.B Landsman (GSFC),
F. E. Marshall (NASA/GSFC), J. P. Osborne (U Leicester),
C. Pagani (PSU), D. M. Palmer (LANL), A. M. Parsons (GSFC),
M. Stamatikos (NASA/ORAU) and E. Troja (INAF-IASFPA) report on behalf
of the Swift Team:

At 20:19:34 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081210 (trigger=337073).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 70.458, -11.266 which is 
   RA(J2000) = 04h 41m 50s
   Dec(J2000) = -11d 15' 55"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a double-peaked
structure with a duration of about 30 sec, followed by an additional
peak at T+140 s.  The peak count rate was ~5000 counts/sec 
(15-350 keV), at ~18 sec after the trigger. 

The XRT began observing the field at 20:20:46.1 UT, 71.9 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 70.4853, -11.2568 which is equivalent to:
   RA(J2000)  = 04h 41m 56.47s
   Dec(J2000) = -11d 15' 24.4"
with an uncertainty of 5.4 arcseconds (radius, 90% containment). This
location is 101 arcseconds from the BAT onboard position, within the
BAT error circle. The full field-of-view light curve shows a strong flare
at T+140 s, coincident with a flare seen in the BAT. No event data are yet
available to determine the column density using X-ray spectroscopy. 

The initial flux in the 2.5 s image was 1.35e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 80 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 04:41:56.20 = 70.48417
  DEC(J2000) = -11:15:26.7  = -11.25741
with a 90%-confidence error radius of about 0.64 arc sec. This position is 4.6
arc sec. from the center of the XRT error circle. The estimated magnitude is
19.12 with a 1-sigma error of about 0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.08.  The afterglow is detected
in the UVOT u filter, so the redshift must be less than approximately 3.3. 

Burst Advocate for this burst is H. A. Krimm (krimm AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081210A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8649
SUBJECT: GRB 081210: Swift-BAT refined analysis
DATE:    08/12/10 23:52:21 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+651 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 081210 (trigger #337073)
(Krimm, et al., GCN Circ. 8648).  The BAT ground-calculated position is
RA, Dec = 70.485, -11.263 deg, which is 
   RA(J2000)  =  04h 41m 56.5s 
   Dec(J2000) = -11d 15' 46.0" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 96%.
 
The mask-weighted light curve shows several peaks.  The first starts at
~T-30 sec.  The second and brightest peaks at ~T+18 sec.  The third peaks
at T+135 sec.  There is possible forth peak at T+180 sec.
T90 (15-350 keV) is 146 +- 8 sec (estimated error including systematics).
 
The time-averaged spectrum from T-12.9 to T+143.0 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.42 +- 0.14.  The fluence in the 15-150 keV band is 1.8 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+17.97 sec in the 15-150 keV band
is 2.5 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/337073/BA/


GRB_name: GRB081210A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8650
SUBJECT: GRB 081210: Enhanced Swift-XRT position
DATE:    08/12/11 01:31:00 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2098 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 081210, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 70.4841, -11.2577 which is equivalent
to:

RA (J2000): 04h 41m 56.19s
Dec (J2000): -11d 15' 27.8"

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081203B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8651
SUBJECT: GRB081203B: optical observations
DATE:    08/12/11 05:43:29 GMT
FROM:    Vladimir Sokolov at SAO RAS  <sokolov@sao.ru>

T.A. Fatkhullin (SAO RAS, Niznij Arkhyz), E. Sonbas (SAO RAS, Niznij Arkhyz; 
University of Cukurova, Turkey), A.J. Castro-Tirado (IAA-CSIC Granada) & 
A.Pozanenko (IKI RAS, Moscow) on behalf of larger collaboration, report:

We observed the field of the GRB081203B (P. Schady et al., GCN 8606; Andreev 
et al, GCN 8608) in the Rc-band with the 6-m telescope of the SAO RAS in 
Caucasus. In total two 3-min exposures were obtained. The optical transient 
(OT) is clearly detected in the both images. Using 4 USNO B1.0
stars we estimated the brightness of the OT as 
R = 21.81 +/- 0.10  at the epoch of  T-T0 = 3.534 days. 
We assumed a burst time of 13:52:02 UT (Copete et al., GCN 8600).

Combining our data with ones from the GCN 8608, 8626, 8631 and 8637 
we estimate the observed power-law index of the light curve as alpha ~ 1.0.

In the same night we also obtained 2x600sec spectrum of the object near 
morning twilight. The VPHG550G grism was used with spectral resolution of 
FWHM=10A. Inspection of the integrated spectrum showed no strong emission 
lines in the range of 4000-7500AA.

The 3-min R-band image can be downloaded from 
ftp://ftp.sao.ru/pub/grb/GRB081203B/GRB081203B_R01.jpg

This message can be cited

[GCN OPS NOTE(13dec08):  Per author's request, the ftp url was corrected.]


GRB_name: GRB081210A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8652
SUBJECT: GRB 081210: Swift-XRT refined analysis
DATE:    08/12/11 09:02:37 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans, K.L. Page (U. Leicester) and H.A. Krimm (CRESST/GSFC/USRA)
report on behalf of the Swift-XRT team:

We have analysed 4.9 ks of XRT data for GRB 081210 (Krimm et al., GCN
Circ. 8648), beginning 78 s after the BAT trigger. The first 387 s were
obtained in Windowed Timing (WT) mode and the remainder in Photon
Counting (PC) mode. The enhanced XRT position for this burst was given
by Osborne et al. (GCN Circ 8650).

The light curve shows an initial period of flaring activity. A strong
peak is seen at T+138 s coincident with the third peak seen by the BAT
(Barthelmy et al. GCN Circ. 8649). Further peaks are seen at T+219 s,
317 s and 391 s. During this time the underlying light curve, while
difficult to constrain, is clearly decaying, with a power-law index of
around 1.5. Around T+5000 s the decay flattens, to a slope of 0.74
(+/-0.24).

A spectrum formed from the PC mode data, i.e. after the flaring activity
has ceased, can be fitted with an absorbed power-law with a photon
index of 1.91 (+/-0.12). The best-fitting absorption column is 6.1
(+2.5, -1.5) x 10^20 cm^-2, consistent with the Galactic value in the
direction of the burst (4.6 x 10^20 cm^-2, Kalberla et al. 2005). The
counts to observed 0.3-10 keV flux conversion factor deduced from this
spectrum is 4.2 x 10^-11 erg cm^-2 count^-1.

If the light curve continues to decay with a power-law decay index of
0.74, the count rate at T+24 hours will be 0.017 count s^-1,
corresponding to an observed (unabsorbed) flux of 6.73 x 10^-13 (8.02 x
10 ^-13) erg cm^-2 s^-1.

The results of the xrt automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00337073.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081211A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8653
SUBJECT: GRB 081211: Swift detection of a burst
DATE:    08/12/11 12:16:45 GMT
FROM:    Hans Krimm at NASA-GSFC  <krimm@milkyway.gsfc.nasa.gov>

H. A. Krimm (CRESST/GSFC/USRA), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), P.A. Curran (MSSL-UCL),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
O. Godet (U Leicester), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), S. D. Hunsberger (PSU),
N. P. M. Kuin (MSSL), V. Mangano (INAF-IASFPA),
C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC),
P. T. O'Brien (U Leicester), J. P. Osborne (U Leicester),
K. L. Page (U Leicester), A. M. Parsons (GSFC),
P. Romano (INAF-IASFPA), R. L. C. Starling (U Leicester),
T. N. Ukwatta (GSFC/GWU) and H. Ziaeepour (UCL-MSSL) report on behalf
of the Swift Team:

At 11:48:10 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081211 (trigger=337115).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 328.087, -33.815 which is 
   RA(J2000) = 21h 52m 21s
   Dec(J2000) = -33d 48' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a weak
structure with a duration of about ~20 sec.  The peak count rate
was ~400 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 11:50:00.6 UT, 109.9 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 328.1161, -33.8361
which is equivalent to:
   RA(J2000)  = 21h 52m 27.85s
   Dec(J2000) = -33d 50' 09.8"
with an uncertainty of 2.3 arcseconds (radius, 90% containment). This
location is 115 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.87e+20
cm^-2, Kalberla et al. 2005), with an excess column of 1.9
(+2.21/-1.92) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 114 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers none of
the XRT error circle. The 8'x8' region for the list of sources generated 
on-board covers 100% of the XRT error circle. The list of sources is 
typically complete to about 18 mag. No correction has been made for 
the expected extinction corresponding to E(B-V) of 0.03. 

Burst Advocate for this burst is H. A. Krimm (krimm AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081210A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8654
SUBJECT: GRB 081210: Swift/UVOT refined analysis
DATE:    08/12/11 18:59:03 GMT
FROM:    Stefan Immler at NASA/GSFC  <stefan.m.immler@nasa.gov>

S. Immler (CRESST/UMD/GSFC), S. T. Holland (CRESST/USRA/GSFC), and H. A. 
Krimm (CRESST/GSFC/USRA) report on behalf of the Swift UVOT team:

Further analysis of Swift Ultraviolet/Optical Telescope (UVOT) data of 
GRB 081210 (Krimm et al., GCN Circ. 8648), starting 80 sec after the BAT 
trigger, gives a detection of an optical source consistent with the 
enhanced XRT position (Osborne et al., GCN Circ 8650) in the white and u 
filters at 12.6-sigma and 3.8-sigma levels of confidence, respectively. 
The source is not detected in any of the other UVOT filters at the 
limiting magnitudes reported below.

Filter Tstart(s) Tstop(s)  Exp(s)  Magnitude

wh      80       1009     318      19.91+/-0.08
u      292        716     265      20.15+/-0.29
b      548        741      39      >19.78  (3-sigma UL)
uvw2   598       5251     235      >20.47  (3-sigma UL)
v      622        816     244      >19.99  (3-sigma UL)
uvm2   647        840     136      >19.55  (3-sigma UL)
uvw1   672        866      39      >18.74  (3-sigma UL)

The values quoted above are in the UVOT photometric system (Poole et al. 
2008, MNRAS, 383, 627) and are not corrected for the expected Galactic 
extinction along the line of sight which corresponds to a reddening of 
E(B-V) = 0.077 mag (Schlegel et al. 1998).

The event data in the white filter shows a flare peaking at 
approximately 130 s after the BAT trigger, which approximately coincides 
with the flare seen in the X-ray light curve (Evans et al., GCN Circ 8652).


GRB_name: GRB081211A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8655
SUBJECT: GRB 081211: Enhanced Swift-XRT position
DATE:    08/12/11 20:12:10 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2165 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 081211, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 328.1163, -33.8364 which is equivalent
to:

RA (J2000): 21h 52m 27.91s
Dec (J2000): -33d 50' 10.9"

with an uncertainty of 1.6 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081211A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8656
SUBJECT: GRB 081211: Swift/UVOT detection of an optical afterglow
DATE:    08/12/11 21:33:35 GMT
FROM:    Stefan Immler at NASA/GSFC  <stefan.m.immler@nasa.gov>

S. Immler (CRESST/UMD/GSFC), S. T. Holland (CRESST/USRA/GSFC), and H. A. 
Krimm (CRESST/GSFC/USRA) report on behalf of the Swift UVOT team:

Further analysis of Swift Ultraviolet/Optical Telescope (UVOT) data of 
GRB 081211 (Krimm et al., GCN Circ. 8653), starting 113 sec after the 
BAT trigger, gives a detection of an optical source within the enhanced 
Swift-XRT position (Beardmore et al., GCN Circ. 8655) at
     RA (J2000)  21:52:27.97 = 328.11654 (deg)
     Dec (J2000) -33:50:08.3 = -33.83565 (deg)
with an uncertainty of 0.7 arcseconds (radius, 90% containment) in the 
white filters at 4.5-sigma level of confidence. The source is not 
present in DSS, the USNO-B1.0 catalogue, or the 2MASS point source 
catalogue. It is not detected in any of the other UVOT filters at the 
limiting magnitudes reported below.

Filter Tstart(s) Tstop(s)  Exp(s)  Magnitude

wh     113       7134     588      21.23+/-0.39
u      326       6724     265      >20.23  (3-sigma UL)
b      582        741     293      >20.24  (3-sigma UL)
uvw2   632       7318     371      >20.40  (3-sigma UL)
v      656      11966     386      >19.38  (3-sigma UL)
uvm2   681       6314     136      >19.58  (3-sigma UL)
uvw1   706       6519     196      >19.87  (3-sigma UL)

The values quoted above are in the UVOT photometric system (Poole et al. 
2008, MNRAS, 383, 627) and are not corrected for the expected Galactic 
extinction along the line of sight which corresponds to a reddening of 
E(B-V)=0.077 mag (Schlegel et al. 1998).


GRB_name: GRB081211A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8657
SUBJECT: GRB 081211: Swift XRT refined analysis
DATE:    08/12/11 22:08:03 GMT
FROM:    Rhaana Starling at U of Leicester  <rlcs1@star.le.ac.uk>

R.L.C. Starling (U. Leicester) and H.A. Krimm (CRESST/GSFC/USRA) report on 
behalf of the Swift XRT team:

We have analysed data from the first 2 orbits of Swift XRT observations of 
GRB 081211 (trigger=337115, Krimm et al. GCN Circular 8653) from 113 s to 
24 ks after the BAT trigger, all collected in Photon Counting (PC) mode.

The enhanced Swift XRT position for this GRB is given in Beardmore et al. 
(GCN Circular 8655).

We confirm that the source is fading, however, the light curve is not well 
constrained at present. A power law fit results in a decay slope of 
alpha=0.6+/-0.1, but we note that flaring may be present from 350-1000 s.

The time-averaged spectrum can be fit with an absorbed power law with 
photon index Gamma=2.4+/-0.3. There is significant absorption above the 
Galactic value (nH_Gal=1.9e20 cm^-2, Kalberla et al. 2005) amounting to a 
column of nH=(1.2+/-0.6)e21 cm^-2 (at z=0). The observed (unabsorbed) 
0.3-10 keV flux is 3.1 (5.0) e-12 erg cm^-2 s^-1. The observed 
(unabsorbed) count rate to flux conversion derived from this spectrum is 1 
count s^-1 = 3.3 (5.3) e-11 erg cm^-2.
The predicted count rate at T+24h, assuming a decay of alpha=0.6, is 0.01
count s^-1.

The results of the XRT automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00337115.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081211A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8658
SUBJECT: GRB 081211: Swift-BAT refined analysis
DATE:    08/12/11 22:42:23 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm@nasa.gov>

Using the data set from T-239 to T+963 sec from the recent telemetry 
downlink,
we report further analysis of BAT GRB 081211 (trigger #337115)
(Krimm, et al., GCN Circ. 8653).  The BAT ground-calculated position is
RA, Dec = 328.082, -33.818 deg which is
   RA(J2000)  =  21h 52m 19.7s
   Dec(J2000) = -33d 49' 05.9"
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 42%.
 
The mask-weighted light curve shows a single weak peak extending in time
from T-1 to T+3 seconds. There is a possible precursor at ~T-180 sec.
T90 (15-350 keV) is 3.5 +- 0.9 sec (estimated error including systematics).
 
The time-averaged spectrum from T-1.1 to T+2.7 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.34 +- 0.41.  The fluence in the 15-150 keV band is 1.3 +- 0.3 x 10^-7 
erg/cm2.
The 1-sec peak photon flux measured from T+0.19 sec in the 15-150 keV band
is 0.8 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/337115/BA/


GRB_name: GRB081210A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8659
SUBJECT: GRB 081210, SMARTS optical/IR observations
DATE:    08/12/12 01:42:28 GMT
FROM:    Bethany Cobb at UC Berkeley  <bcobb@astro.berkeley.edu>

B. E. Cobb (UC Berkeley) reports:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained optical/IR imaging of the error region of GRB 081210
(Krimm et al. GCN 8648) with a mid-exposure time of ~6.2 hours
post-burst (2008-12-11 02:33 UT).  Total summed exposure
times amounted to 36 minutes in I and 30 minutes in J.

The GRB's optical afterglow (Krimm et al. GCN 8648)
is not detected to an approximate limiting magnitude
of I>22.3 and J>20.0.  (Optical photometry is calibrated against
Landolt standard stars and IR photometry is calibrated
against 2MASS stars in the field.)


GRB_name: GRB081210A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8660
SUBJECT: GRB 081210:  Xinglong TNT R band Upper Limits
DATE:    08/12/12 03:12:49 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

X.F. Wang, L.P. Xin, Y.L. Qiu, J.Y. Wei, j. Wang, J.Y. Hu, 
J.S. Deng, W.K. Zheng on behalf of EAFON report:

We have observed GRB081210 (Krimm et al, GCN 8648) 
with Xinglong TNT telescope from Dec.11th,13:38:47(UT),
17.33 hr after the burst. After combined 6*600s R band
images, no afterglow was detected with the 3 sigma 
upper limits of 19.571, at the mean time of 17.814 hr 
after the burst.

This message may be cited.

For more information about Xinglong GRBs Follow-up 
observations, please visit the website:
http://www.xinglong-naoc.org/grb/


GRB_name: GRB081007A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8662
SUBJECT: GRB 081007: Detection of a Supernova
DATE:    08/12/12 16:46:46 GMT
FROM:    Edo Berger at Harvard  <eberger@cfa.harvard.edu>

Alicia Soderberg, Edo Berger (Harvard CfA), and Derek Fox (PSU) report on
behalf of a larger collaboration:

"We imaged the optical counterpart of GRB 081007 (Baumgartner et al., GCN
8330) with Gemini-S/GMOS in the griz filters on three separate epochs: Oct
24.02, Nov 2.01, and Dec 5.04 UT corresponding to 16.80, 25.79, and 58.82
days after the burst, respectively.

Using the ISIS image subtraction package and adopting our third epoch as a
template image, we find a residual source in the first and second epochs
at a position coincident with that of the early afterglow.  A comparison
of the residual flux indicates that the transient increased by roughly 0.4
mag in i-band between the first and second epochs and then subsequently
faded.  We attribute this photometric evolution to a supernova component,
in line with the recent report of spectroscopic evidence for an underlying
Type Ibc supernova (Della Valle et al., CBET 1602).

Accounting for a redshift of z=0.53 (Berger et al., GCN 8335), the
k-corrected absolute magnitude of the object in our second epoch i-band
image is fainter than that SN 1998bw at the same (rest-frame) time.

Further analysis is on-going."


