# GCN_circulars

GRB_name: GRB171010A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22012
SUBJECT: GRB 171010A : Optical observations from HCT
DATE:    17/10/13 18:11:40 GMT
FROM:    D.K. Sahu at Indian Inst of Astrophysics,Bangalore  <dks@iiap.res.in>

GRB 171010A : Optical observations from HCT

Brajesh Kumar,  D.K. Sahu, G.C. Anupama  and Avinash Singh (Indian
Institute of Astrophysics, Bangalore, India) communicate on behalf
of a larger Indian collaboration.

We observed the Fermi LAT GRB 171010A (Omodei et al., GCN 21985)
field with the 2-m Himalayan Chandra Telescope (HCT) located at
Indian Astronomical Observatory, Hanle, India.
Multiple frames in Bessell's R and I bands were obtained starting
from 18:43 UT on October 11, 2017. The optical afterglow candidate
(Thorstensen and Halpern, GCN 21987; Izzo and  Malesani, GCN 21988;
Guidorzi et al., GCN 21991; Malesani et al., GCN 22000; Harita et al.,
GCN 22001; Breeveld and Siegel, GCN 22004) was detected in our
individual frames.

The preliminary magnitudes of the OT, calibrated using nearby USNO
stars are as follows:
-------------------------------------------------------------------
  Date          Mid UT      Exp (sec)  Filter   Magnitude
  (YYYY-MM-DD)              time
-------------------------------------------------------------------
  2017-10-11    18:46       300          R      18.31 +/- 0.05
  2017-10-11    18:54       300          R      18.38 +/- 0.05
  2017-10-11    20:12       450          R      18.42 +/- 0.04
  2017-10-11    21:32       300          R      18.48 +/- 0.05
  2017-10-11    21:46       300          R      18.51 +/- 0.05
-------------------------------------------------------------------
  2017-10-11    20:21       300          I      18.06 +/- 0.05
  2017-10-11    20:28       300          I      18.09 +/- 0.05
  2017-10-11    21:53       300          I      18.22 +/- 0.05
  2017-10-11    22:00       300          I      18.24 +/- 0.05
--------------------------------------------------------------------

Contamination due to the host galaxy has not been removed.


GRB_name: GRB171010A
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22013
SUBJECT: GRB 171010A: A detection of a radio source by AMI
DATE:    17/10/13 20:36:14 GMT
FROM:    Assaf Horesh at Hebrew U, Jerusalem  <assafh@mail.huji.ac.il>

Assaf Horesh (HUJI), Joe Bright, K. P. Mooley, T. D. Staley, R. P. Fender (Oxford), G. E. Anderson 
(Curtin), T. Cantwell (Manchester), D. Titterington, S. H. Carey, J. 
Hickish, Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. 
Grainge, A. Scaife (Manchester) report:

The AMI Large Array triggered on the Fermi-LAT alert for GRB 171010A (Omodei et al., GCN 21985) as part of the 4pisky program. Our initial observations at 15.5 GHz on 2017 Oct 12 reveal an unresolved radio source consistent with the XRT afterglow location (D'Ai et al., GCN 21989), with a flux of ~2.5 mJy. Please note that due to the large AMI beam in this case (~ 100x30 arc-second), the detected source may be contaminated by other radio sources. However, the nearest radio source detected in the NVSS archival data is 6.9 arc-minute away. Further analysis is in progress and future AMI observations are planned. We encourage further radio followup observations. 

We thank the AMI staff for scheduling these observations. The AMI-GRB 
database is a log of all GRB follow up observations with the AMI, and is 
available at http://4pisky.org/ami-grb/ <http://4pisky.org/ami-grb/>.


GRB_name: GRB171010A
Detection_method: VLA Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22014
SUBJECT: GRB 171010A: VLA Detection
DATE:    17/10/13 20:55:59 GMT
FROM:    Tanmoy Laskar at UC Berkeley  <tanmoylaskar@gmail.com>

T. Laskar (NRAO / UC Berkeley), D. L. Coppejans, and R. Margutti
(Northwestern University) report on behalf of a larger collaboration:

"We observed GRB 171010A (Omodei et al.; GCN 21985) at multiple frequencies
with the VLA beginning on 2017 October 13.32 UT (2.79 days after the
burst). At a mean frequency of 6 GHz, we detect a radio source with a
preliminary flux density of ~ 0.7 mJy at

RA = 04:26:19.4780 +/- 0.0005
Dec = -10:27:46.03 +/- 0.01

consistent with the Swift/XRT position (D'Ai et al.; GCN 21989) and the
optical position (Halpern et al.; GCN 21987, Izzo et al.; GCN 21988).
Follow-up observations are planned. We thank the VLA staff for rapidly
scheduling these observations."


GRB_name: GRB171010A
Detection_method: VLA Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22015
SUBJECT: GRB 171010A: VLA Observations
DATE:    17/10/15 05:36:34 GMT
FROM:    Assaf Horesh at Hebrew U, Jerusalem  <assafh@mail.huji.ac.il>

A. Horesh (HUJI), D. A. Perley (LJMU), S. B. Cenko (NASA/GSFC) report: 

We observed GRB171010A (Omodei et al., GCN 21985) with the Jansky Very Large Array (VLA) under our Fermi  GRB program. The VLA observations were undertaken on 2017 October 13.35 UT. We detected a radio source with a flux of ~1.5 mJy at a central frequency of 10 GHz. The source position is consistent with the position of the reported afterglow (Thorstensen and Halpern, GCN 21987; Izzo and Malesani, GCN 21988; Guidorzi et al., GCN 21991; Malesani et al., GCN 22000; Harita et al., GCN 22001; Breeveld and Siegel, GCN 22004; Watson et al., GCN 22011; Kumar et al., GCN 22012). 

Our observations thus confirm the earlier reports of a radio detection (Horesh et al. GCN 22013; Laskar et al. GCN 22014) and suggest that the radio source has a rising spectrum towards higher frequencies. 

Further VLA observations are planned. 
We thank the VLA staff for scheduling these observations.


GRB_name: GRB171011B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22022
SUBJECT: GRB 171011B CALET Gamma-Ray Burst Monitor detection
DATE:    17/10/18 11:57:19 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

P. S. Marrocchesi (U of Siena), A. Yoshida, T. Sakamoto, Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U),
S. Nakahira (RIKEN), I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni (U of Siena)
and the CALET collaboration:

The long-duration GRB 171011B (Hurley et al., GCN Circ. 21998;
Svinkin et al., GCN Circ. 22005) triggered the CALET Gamma-ray Burst Monitor (CGBM)
at 01:05:36.47 on 11 October 2017.  The burst signal was seen by the all CGBM instruments.

The light curve of the SGM shows a single peak.  The emission starts at T0 sec
and the brightest pulse peaks at T+1.5 sec.  The entire emission ends at T+3.5 sec.
The T90 duration measured by the SGM data is 2.0 +- 0.3 sec (40-1000 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1191719089/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB171010B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22023
SUBJECT: GRB 171010B: Swift-XRT afterglow detection
DATE:    17/10/18 13:07:12 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

A. Melandri (INAF-OAB), D.N. Burrows (PSU), A. Tohuvavohu (PSU), S. J.
LaPorte (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester),
A.P. Beardmore (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC)
and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has conducted further observations of the field of the
Swift/BAT-detected burst GRB 171010B (Palmer et al. GCN Circ. 21995).
The observations now extend from T0+91.1 ks to T0+614.5 ks. 

Of the sources reported by Sbarufatti et al. (GCN Circ. 22009), "Source
2" is  believed to be the afterglow.  The position of this source is
RA, Dec=34.1342, -54.3915 which is equivalent to:

RA (J2000): 02:16:32.20
Dec(J2000): -54:23:29.2

with an uncertainty of 5.6 arcsec (radius, 90% confidence).  This
position is 71 arcsec from the Swift/BAT position. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.8 (+0.6, -0.4).

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020780.
The results of the full analysis of the XRT observations are available
at http://www.swift.ac.uk/ToO_GRBs/00020780.

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


GRB_name: GRB171011B
Detection_method: Insight-HXMT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22026
SUBJECT: GRB 171011B: Insight-HXMT detection
DATE:    17/10/19 09:45:28 GMT
FROM:    Juan Zhang at IHEP/CAS/POLAR  <zhangjuan@ihep.ac.cn>

J. Zhang, J. Y. Liao, C. K. Li, X. B. Li, Y. Huang, S. L. Xiong, 
C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, X. F. Lu, J. L. Zhao, 
C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU),
F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, Y. P. Xu, 
A. M. Zhang, Y. F. Zhang, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:


During the commissioning phase, at 2017-10-11T01:05:36 (T0),
Insight-HXMT/HE detected GRB 171011B (trigger ID: HEB171011045)
in a routine search of the data, which is also detected by CALET
(Marrocchesi et al., GCN 22022) and INTEGRAL, etc. 
This burst has been localized by IPN triangulation
(Hurley et al., GCN Circ. 21998).


The Insight-HXMT light curve consists of multi-pulses
with a duration (T90) of 1.6 s measured from T0+1.3 s to T0+2.9 s.
The 20-ms peak rate, measured from T0+1.98 s, is 23852.4 cnts/sec.
The total counts from this burst is 19179.3 counts.


URL_LC: http://www.hxmt.org/images/GRB/HEB171011B_LC.pdf


The time-averaged spectrum from T0-1 s to T0+7 s is
adequately fit by a Band spectrum with alpha = 3.94 +/- 0.86, 
beta = -2.65 +/- 0.16 and E_peak = 339.29 +/- 19.71.
The energy fluence is (5.45 +/- 0.24)E-05 erg/cm^2 in 200 - 5000 keV 
in this time interval.


All measurements above are made with the CsI detectors operating in the 
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside 
of the telescope.


The analysis results presented above are preliminary;
final results will be published elsewhere.


Insight-HXMT is the first Chinese space X-ray telescope, which was funded
jointly by the China National Space Administration (CNSA) and the Chinese
Academy of Sciences (CAS). More information about it could be found at: 
http://www.hxmt.org/index.php/enhome .


GRB_name: GRB171020A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22028
SUBJECT: GRB 171020A: Swift detection of a burst
DATE:    17/10/20 23:28:53 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

K. L. Page (U Leicester), A. P. Beardmore (U Leicester),
J.D. Gropp (PSU), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL),
A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC),
B. Sbarufatti (PSU) and M. H. Siegel (PSU) report on behalf of the
Swift Team:

At 23:07:10 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 171020A (trigger=780845).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 39.262, +15.186 which is 
   RA(J2000) = 02h 37m 03s
   Dec(J2000) = +15d 11' 10"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 50 sec.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~2 sec after the trigger. 
Note that the BAT light curve might be contaminated by Swift J0243.6+6124,
which has a period of 9.86 s (ATel #10809). 

The XRT began observing the field at 23:09:35.2 UT, 144.4 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 39.2482,
15.2038 which is equivalent to:
   RA(J2000)  = 02h 36m 59.57s
   Dec(J2000) = +15d 12' 13.5"
with an uncertainty of 2.2 arcseconds (radius, 90% containment). This
location is 80 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 1.55
x 10^21 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 147 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
0.19. 

Burst Advocate for this burst is K. L. Page (klp5 AT leicester.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: GRB171020A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22029
SUBJECT: GRB 171020A: NOT optical afterglow detection
DATE:    17/10/21 00:19:15 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani (DARK/NBI), M. Stone (Turku Univ.), K. Karhunen (Turku 
Univ.), A. de Ugarte Postigo (IAA/CSIC and DARK/NBI), and D. Xu 
(NAOC/CAS), report on behalf of a larger collaboration:

We observed the field of GRB 171020A (Page et al., GCN 22028) with the 
Nordic Optical Telescope equipped with the AlFOSC imager and 
spectrograph. Observations were carried out in the r and z filters, 
starting on 2017 Oct 20.979 UT (22.9 min after the trigger).

Within the XRT error circle, we detect an uncatalogued source at 
coordinates (J2000):

RA = 02:36:59.62
Dec = +15:12:16.0

By comparison with nearby stars from the Pan-STARRS catalog, we measure 
r = 20.98 +- 0.03 AB. As this object is not visible in the deeper, 
archival Pan-STARRS images, and given the coincidence with the X-ray 
counterpart, we suggest this object to be the optical afterglow of GRB 
171020A.


GRB_name: GRB171020A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22030
SUBJECT: GRB 171020A: Mini-MegaTORTORA upper limits on simultaneous optical emission
DATE:    17/10/21 00:31:17 GMT
FROM:    Sergey Karpov at SAO RAS  <karpov@sao.ru>

S.Karpov, G.Beskin (SAO RAS and Kazan Federal University, Russia), S.Bondar,
E.Ivanov, E.Katkova, N.Orekhova, A.Perkov (OJS RPC PSI, Russia), A.Biryukov
(SAI MSU and Kazan Federal University, Russia), V.Sasyuk (Kazan Federal
University, Russia)

Mini-MegaTORTORA nine-channel wide-field monitoring system with high
temporal resolution has been observing the Swift field of view before,
during and after the time of Swift BAT trigger corresponding to GRB171020A
(Page et al, GCN 22028). The whole burst localization region has been
covered since 2017-10-20 23:00:07.90 UT (T0-422 s) and until 2017-10-20
23:10:17.68 UT (T0+187 s, thus including the whole gamma-ray activity
interval) with temporal resolution of 0.1 s in white light. Dedicated
real-time transient detection pipeline did not detect any events longer
than 0.3 s and brighter than approximately V=10.5 mag during this interval.
Visual inspection of co-added images with 10 s effective exposure
(summation of 100 consecutive frames each) has not revealed any variable
source down to V=12.0 mag during that interval. Also, the multi-regime
follow-up (when all channels except for the one containing the trigger are
repointed towards it and observe it with various exposures with and without
photometric and polarimetric filters installed) has been initiated at
2017-10-20 23:08:12.0 UT (T0+61.25 s). The inspection of 10 s exposure
frames acquired in white light between 2017-10-20 23:08:12.0 UT (T0+61.25
s) and 2017-10-20 23:09:43 UT (T0+152.25 s) did not reveal any source
brighter than V=13.5 mag at the position of the burst.

Mini-MegaTORTORA belongs to Kazan Federal University and is located at
Special Astrophysical Observatory near Russian 6-m telescope.

The message may be cited.


GRB_name: GRB171020A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22031
SUBJECT: GRB 171020A: Confirmation of OT fading
DATE:    17/10/21 03:32:12 GMT
FROM:    Moskvitin Alexander at SAO RAS  <mosk@sao.ru>

A. Moskvitin (SAO RAS), O. Spiridonova (SAO RAS), A. Volnova (IKI RAS)

We observed the field of GRB 171020A (Page et al., GCN 22028)
with the 1-m telescope of SAO RAS, Zeiss-1000 on 2017.10.20,
starting at 23:18 UT, i.e. ~11 minutes after the trigger.
The OT (Malesani et al., GCN 22029) is clearly detected
in the individual 300 sec. frames. The coordinates of OT:
R. A. = 02:36:59.62; Dec. = +15:12:15.6 (J2000).


Date       UT start  t - T0       Filter Exp.  OT       Err.  UL
                     (mid, days)         (s)

2017.10.20 23:18:05  0.02016      Rc     6*300 20.9 +/- 0.1   22.3
           23:55:27  0.04827      Rc     7*300 21.5 +/- 0.1   22.5



The temporal decay slope is about -0.3, F ~ (t-T0)^alpha.

The calibration were made against the nearby USNO-B1.0 stars
(R2 magnitudes):
1051-0026883 02:37:00.38 +15:11:09.6 18.59
1052-0027787 02:36:57.49 +15:12:36.8 16.62
1052-0027776 02:36:50.26 +15:12:39.8 18.15


GRB_name: GRB171020A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22032
SUBJECT: GRB 171020A: Correction of alpha in GCN 22031
DATE:    17/10/21 03:49:17 GMT
FROM:    Moskvitin Alexander at SAO RAS  <mosk@sao.ru>

A. Moskvitin (SAO RAS), O. Spiridonova (SAO RAS), A. Volnova (IKI RAS)

In our previous GCN 22031 we reported incorrect slope.
The correct decay slope is about -0.6 +/- 0.2.

We apologize for any confusion caused by the earlier report.


GRB_name: GRB171020A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22033
SUBJECT: GRB 171020A: LT observations
DATE:    17/10/21 06:30:48 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell (U. Bath), 
A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU) on behalf of a large 
collaboration report:

The 2-m Liverpool Telescope automatically began observing Swift GRB 
171020A (Page et al. GCN 22028) on October 20, 23:10:12 UT (3.0 minutes 
from the GRB trigger time) with the RINGO3 polarimeter and the IO:O 
camera in the SDSS-R filter. We clearly detect the optical afterglow 
(Malesani et al, GCN 22029; Moskvitin et al., GCN 22031) with the 
following magnitude:

Mid Time      Exposure       Filter       Magnitude (AB)
(min)           (s)
-------------------------------------------------------
35.8            6x10         SDSS-R       21.12 +- 0.14
-------------------------------------------------------

as calibrated against nearby Pan-STARRS objects.


GRB_name: GRB171020A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22034
SUBJECT: GRB 171020A: Enhanced Swift-XRT position
DATE:    17/10/21 08:10:11 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 5393 s of XRT Photon Counting mode data and 8 UVOT
images for GRB 171020A, 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 = 39.24837, +15.20413 which is equivalent
to:

RA (J2000): 02h 36m 59.61s
Dec (J2000): +15d 12' 14.9"

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) and Evans
et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB171020A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22035
SUBJECT: GRB 171020A: Swift-XRT refined Analysis
DATE:    17/10/21 10:34:06 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. Tohuvavohu (PSU), S. J. LaPorte (PSU), J.A. Kennea (PSU), A.P.
Beardmore (U. Leicester), P.A. Evans (U. Leicester), P. D'Avanzo
(INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA) and K.L. Page
report on behalf of the Swift-XRT team:

We have analysed 7.5 ks of XRT data for GRB 171020A (Page et al. GCN
Circ. 22028), from 128 s to 35.4 ks after the  BAT trigger. The data
comprise 10 s in Windowed Timing (WT) mode (taken while Swift was
slewing), with the remainder in Photon Counting (PC) mode. The enhanced
XRT position for this burst was given by Evans et al. (GCN Circ.
22034).

The light curve can be modelled with an initial power-law decay with an
index of alpha=2.23 (+0.45, -0.21), followed by a break at T+563 s to
an alpha of 0.88 (+0.08, -0.07).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.58 (+0.17, -0.15). The
best-fitting absorption column is  1.84 (+0.70, -0.28) x 10^21 cm^-2,
consistent with the Galactic value of 1.6 x 10^21 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 4.5 x 10^-11 (5.3 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.84 (+0.70, -0.28) x 10^21 cm^-2
Galactic foreground: 1.6 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.58 (+0.17, -0.15)

If the light curve continues to decay with a power-law decay index of
0.88, the count rate at T+24 hours will be 5.4 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.4 x
10^-13 (2.9 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00780845.

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


GRB_name: GRB171020A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22036
SUBJECT: R: GRB 171020A: Swift-XRT refined Analysis
DATE:    17/10/21 13:00:44 GMT
FROM:    Remo Rufinni at ICRA  <ruffini@icra.it>

again a very energetic one. please see R 
Prof. Remo Ruffini
Director of ICRANet
Piazza della Repubblica 10
65122 Pescara (PE)  Italy
mobile: +39 339 4752566
Tel. Rome +39 06 49914304
Tel. Pescara +39 085 23054201
Fax: +39 085 4219252
e-mail: ruffini@icra.it
________________________________________
Da: GCN Circulars [gcncirc@capella2.gsfc.nasa.gov]
Inviato: sabato 21 ottobre 2017 12.46
A: Remo Ruffini - Icra
Oggetto: GRB 171020A: Swift-XRT refined Analysis

TITLE:   GCN CIRCULAR
NUMBER:  22035
SUBJECT: GRB 171020A: Swift-XRT refined Analysis
DATE:    17/10/21 10:34:06 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. Tohuvavohu (PSU), S. J. LaPorte (PSU), J.A. Kennea (PSU), A.P.
Beardmore (U. Leicester), P.A. Evans (U. Leicester), P. D'Avanzo
(INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA) and K.L. Page
report on behalf of the Swift-XRT team:

We have analysed 7.5 ks of XRT data for GRB 171020A (Page et al. GCN
Circ. 22028), from 128 s to 35.4 ks after the  BAT trigger. The data
comprise 10 s in Windowed Timing (WT) mode (taken while Swift was
slewing), with the remainder in Photon Counting (PC) mode. The enhanced
XRT position for this burst was given by Evans et al. (GCN Circ.
22034).

The light curve can be modelled with an initial power-law decay with an
index of alpha=2.23 (+0.45, -0.21), followed by a break at T+563 s to
an alpha of 0.88 (+0.08, -0.07).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.58 (+0.17, -0.15). The
best-fitting absorption column is  1.84 (+0.70, -0.28) x 10^21 cm^-2,
consistent with the Galactic value of 1.6 x 10^21 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 4.5 x 10^-11 (5.3 x
10^-11) erg cm^-2 count^-1.

A summary of the PC-mode spectrum is thus:
Total column:        1.84 (+0.70, -0.28) x 10^21 cm^-2
Galactic foreground: 1.6 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:        1.58 (+0.17, -0.15)

If the light curve continues to decay with a power-law decay index of
0.88, the count rate at T+24 hours will be 5.4 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.4 x
10^-13 (2.9 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00780845.

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


GRB_name: GRB171020A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22037
SUBJECT: GRB 171020A: RATIR Optical and NIR Observations
DATE:    17/10/21 15:28:40 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), JesÃºs
GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey Moseley (GSFC), John
Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:

We observed the field of GRB 171020A (Page, et al., GCN 22028) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on
Sierra San Pedro MÃ¡rtir from 2017/10 21.16 to 2017/10 21.50 UTC (4.60 to
12.98 hours after the BAT trigger), obtaining a total of 5.30 hours
exposure in the r and i bands and 2.20 hours exposure in the Z, Y, J, and H
bands.

We detect the NOT optical transient (Malesani, et al., GCN 22029), which
continues to fade (see also, Moskvitin, et al., GCN 22031).  In comparison
with the USNO-B1 and 2MASS catalogs, we obtain the following detections and
upper limit (3-sigma):

 r = 22.91 +/- 0.12
 i = 22.76 +/- 0.11
 Z > 21.44
 Y = 21.72 +/- 0.35
 J = 21.54 +/- 0.23
 H = 21.69 +/- 0.35

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB171020A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22038
SUBJECT: GRB 171020A: Swift-BAT refined analysis
DATE:    17/10/21 15:54:40 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC), 
J. R. Cummings (CPI), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), K. L. Page (U Leicester)
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 171020A (trigger #780845)
(Page et al., GCN Circ. 22028).  The BAT ground-calculated position is
RA, Dec = 39.260, 15.199 deg which is 
  RA(J2000)  =  02h 37m 02.3s 
  Dec(J2000) = +15d 11' 57.0" 
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 48%.

The mask-weighted light curve shows a weak pulse that starts at ~T0 and 
ends at ~ T+45 s. T90 (15-350 keV) is 41.9 +- 9.2 sec (estimated error 
including systematics).

The time-averaged spectrum from T-0.97 to T+46.68 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.04 +- 0.20.  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+19.92 sec in the 15-150 keV band
is 0.7 +- 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/780845/BA/


GRB_name: GRB171020A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22039
SUBJECT: GRB 171020A: NOT spectroscopic redshift
DATE:    17/10/21 16:43:25 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani (DARK/NBI), J. P. U. Fynbo (NBI), K. E. Heintz (Univ. 
Iceland and DARK/NBI), M. Stone (Turku Univ.), K. Karhunen (Turku 
Univ.), report on behalf of a larger collaboration:

Following our imaging sequence (Malesani et al., GCN 22029), we secured 
spectra of the optical afterglow of GRB 171020A (Page et al., GCN 
22028), using the AlFOSC spectrograph at the Nordic Optical Telescope. A 
total of 4x1200 s exposure was secured using grism #4, covering the 
wavelength range ~3600-9400 AA. Spectroscopy started on 2017 Oct 21.005 
UT (1 hr after the trigger).

A faint trace is detected down to at least ~4000 A. Several weak 
absorption features are detected, which we interpret as due to Mg II, Fe 
II, and C IV all at a common redshift z = 1.87.

We thank the NOT staff for support, in particular Amanda Djupvik and 
Sergio Armas.


GRB_name: GRB171020A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22040
SUBJECT: GRB 171020A: Swift/UVOT Upper Limits
DATE:    17/10/22 06:43:09 GMT
FROM:    Sam LaPorte at PSU  <sjl5346@psu.edu>

GRB 171020A: Swift/UVOT Upper Limits

S. J. LaPorte (PSU) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 171020A
147 s after the BAT trigger (Page et al., GCN Circ. 22028).
No optical afterglow consistent with the XRT position
(Page et al. GCN Circ. 22028)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           147          297          147         >20.6
u_FC               306          556          246         >20.2
white              147         7652          811         >21.4
v                  636         6640          338         >19.4
b                  562         7460          529         >20.8
u                  306         7254          756         >20.2
w1                 686         7050          491         >20.7
m2                6645         6845          197         >20.3
w2                1016         6435          216         >20.3

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.19 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB171020A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22041
SUBJECT: GRB 171020A: TAROT Calern observatory optical observations
DATE:    17/10/22 13:08:21 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

Klotz A., Noysena.K., Atteia J.L. (CNRS-OMP-IRAP),
Boer, M., Eymar, L. (CNRS-ARTEMIS),
Gendre B. (UVI - Etelman Obs.) report:

We imaged the field of GRB 171020A detected by SWIFT
(trigger 780845) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 68s after the GRB trigger
(13s after the notice). The elevation of the field
increased from 58 degrees above horizon and weather
conditions were good.

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 with a limiting magnitude of:
t0+68s to t0+128s : Rlim = 17.5

The OT (Malesani et al., GCN 22029) is detected
in the median of three individual frames:
t0+141s to t0+251s : R = 18.7 +/- 0.35

We co-added a series of exposures. The OT is no
longer detected:
t0+262s to t0+533s : Rlim = 18.9

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


GRB_name: GRB171020A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22042
SUBJECT: GRB 171020A: Continued RATIR Optical and NIR Observation
DATE:    17/10/22 21:19:00 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), JesÃºs
GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey Moseley (GSFC), John
Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:

We observed the field of GRB 171020A (Page, et al., GCN 22028) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on
Sierra San Pedro MÃ¡rtir from 2017/10 22.13 to 2017/10 22.47 UTC (27.94 to
36.23 hours after the BAT trigger), obtaining a total of 5.27 hours
exposure in the r and i bands and 2.21 hours exposure in the Z and Y bands.

We contine to detect the optical transient (Malesani, et al., GCN 22029;
also, Moskvitin, et al., GCN 22031; Butler, et al., GCN 22037).  In
comparison with the USNO-B1 and 2MASS catalogs, we obtain the following
detections and upper limits (3-sigma):

 r = 23.25 +/- 0.14
 i = 23.01 +/- 0.11
 Z > 21.75
 Y > 22.05

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  Compared to our observations last
night, these data suggest either a slow afterglow fade (~t^-0.2) or that
our measured flux contains flux from the GRB host galaxy.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB171022A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22045
SUBJECT: GRB 171022A: Fermi-LAT detection
DATE:    17/10/23 15:27:39 GMT
FROM:    Elisabetta Bissaldi at U.Innsbruk/IAPP  <Elisabetta.Bissaldi@uibk.ac.at>

M. Palatiello (Univ & INFN Trieste), E. Bissaldi (Poiltecnico & INFN Bari),
M. Axelsson (Stockholm Univ.), M. Yassine (Univ & INFN Trieste),
S. Buson  (NASA/GSFC) and J. Racusin (NASA/GSFC)
report on behalf of the Fermi-LAT team:


On September 22, 2017, Fermi-LAT detected high-energy emission from GRB 171022A,
which was also detected by Fermi-GBM (trigger 530399665) at 21:14:20.77 UTC.

The best LAT on-ground location is found to be

RA, Dec 204.28, 10.98 (degrees, J2000),

with an error radius of 0.16 deg (90% containment, statistical error only).
This position was outside the LAT FoV at the time of the GBM trigger,
and entered the FoV at ~T0+3000s.

The Fermi-LAT data show a significant increase
in the event rate within 12 degrees of the GBM location.
More than 20 photons above 100 MeV are observed between
T0+3000 s and T0+6000 s. The highest-energy photon is a 14 GeV event
which is observed ~4600 seconds after the GBM trigger.

A Swift ToO will not be performed for this GRB due to Sun constraints.

The Fermi-LAT point of contact for this burst is
Michele Palatiello (michele.palatiello@ts.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.


GRB_name: GRB171022A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22046
SUBJECT: GRB 171022A: Fermi GBM detection
DATE:    17/10/23 22:38:55 GMT
FROM:    Rachel Hamburg at UAH  <rkh0007@uah.edu>

R. Hamburg (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 21:14:20.77 UT on 22 October 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171022A (trigger 530399665 / 171022885).
which was also detected by the Fermi/LAT
(Palatiello et al. 2017, GCN 22045).
The GBM on-ground location is consistent with the LAT position.

The angle from the Fermi LAT boresight at the GBM trigger time is 99
degrees.

The GBM light curve shows a multi-peaked structure
with a duration (T90) of about 13 s (50-300 keV).
The time-averaged spectrum from T0-0.00 s to T0+15.07 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.49 +/- 0.06 and
the cutoff energy, parameterized as Epeak, is 151 +/- 5 keV.

The event fluence (10-1000 keV) in this time interval is
(8.1 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+3.23 s in the 10-1000 keV band
is 8.7 +/- 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: GRB171013B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22050
SUBJECT: GRB 171013B CALET Gamma-Ray Burst Monitor detection
DATE:    17/10/26 00:55:07 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama, Y. Yamada, A. Tezuka,
S. Matsukawa (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 171013B (Fermi-GBM trigger #529575887) triggered the
CALET Gamma-ray Burst Monitor (CGBM) at 08:24:45.797 on 13 October 2017.
The burst signal was seen by the all CGBM instruments.

The light curve of the SGM shows a single peak.  The emission starts at T0 sec,
peaks at T+17 sec and ends at T+26 sec.  The T90 duration measured by the
SGM data is 18.9 +- 1.5 sec (40-1000 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1191918235/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB171022A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22051
SUBJECT: IPN Triangulation of GRB 171022A
DATE:    17/10/26 18:03:20 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team, and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

The long-duration GRB 171022A
(Fermi-LAT detection: Palatiello et al., GCN Circ. 22045;
Fermi-GBM detection: Hamburg and Meegan, GCN Circ. 22046)
was detected by Fermi (GBM trigger 530399665), Konus-Wind,
INTEGRAL (SPI-ACS), and Mars-Odyssey (HEND)
at about 76461 s UT (21:14:21).

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   215.353 (14h 21m 25s) +12.844 (+12d 50' 37")
  Corners:
   217.045 (14h 28m 11s)  +1.841 ( +1d 50' 29")
   211.510 (14h 06m 02s) +21.802 (+21d 48' 06")
   210.607 (14h 02m 26s) +22.804 (+22d 48' 14")
   216.812 (14h 27m 15s)  +3.167 ( +3d 10' 03")
  ---------------------------------------------
The error box area is 4.1 sq. deg, and its maximum
dimension is 21.9 deg (the minimum one is 12.0 arcmin).
The Sun distance was 16 deg.

This box may be improved.

The Fermi (LAT) on-ground location (RA, Dec, Rerr = 204.28, 10.98, 0.16 
deg) reported in Palatiello et al. is inconsistent with the box, the 
minimum distance between the box and the Fermi (LAT) location is ~11 deg.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB171022_T76456/IPN

The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.


GRB_name: GRB171022A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22052
SUBJECT: Konus-Wind observation of GRB 171022A
DATE:    17/10/26 18:49:24 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 171022A (Fermi-LAT detection: Palatiello et al.,
GCN 22045; Fermi-GBM detection: Hamburg and Meegan, GCN 22046;
IPN Triangulation: Hurley et al., GCN 22051)
triggered Konus-Wind at T0=76456.523 s UT (21:14:16.523).

The KW light curve shows a multi-peaked emission complex
with a total duration of ~15 s. A much weaker pulse is also
seen in the softest KW light curve around ~T0+215 s.
The emission is seen up to ~3.5 MeV.

As observed by Konus-Wind, the burst had a fluence of
(7.1 Â± 0.7)x10^-6 erg/cm2 and a 64-ms peak energy flux,
measured from T0+3.328, of (2.4 Â± 0.2)x10^-6 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+16.640 s)
is best fit in the 20 keV - 15 MeV range by a cutoff power-law
(CPL) function with the following model parameters:
the photon index alpha = -0.51(-0.30,+0.34),
and the peak energy Ep = 144(-13,+17) keV,
chi2 = 93/98 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep, and an upper limit on beta of -2.7,
chi2 = 93/97 dof.

The spectrum near the peak count rate (measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range by the CPL function
with the following model parameters:
the photon index alpha = -0.40(-0.27,+0.30),
and the peak energy Ep = 146(-12,+14) keV,
chi2 = 111/98 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep, and an upper limit on beta of -2.8,
chi2 = 110/97 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB171022_T76456/

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.


GRB_name: GRB171027A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22053
SUBJECT: GRB 171027A: Swift detection of a burst
DATE:    17/10/27 08:40:01 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

P. D'Avanzo (INAF-OAB), P. A. Evans (U Leicester),
N. P. M. Kuin (UCL-MSSL), K. L. Page (U Leicester),
D. M. Palmer (LANL) and B. Sbarufatti (PSU) report on behalf of the
Swift Team:

At 08:23:06 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 171027A (trigger=783479).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 61.680, -2.606 which is 
   RA(J2000) = 04h 06m 43s
   Dec(J2000) = -02d 36' 21"
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 120 sec.  The peak count rate
was ~4000 counts/sec (15-350 keV), at ~60 sec after the trigger. 

The XRT began observing the field at 08:24:34.1 UT, 87.6 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 61.68989, -2.62100
which is equivalent to:
   RA(J2000)  = 04h 06m 45.57s
   Dec(J2000) = -02d 37' 15.6"
with an uncertainty of 3.6 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 in excess of the Galactic value (1.08 x
10^21 cm^-2, Willingale et al. 2013), with an excess column of 2.9
(+2.47/-2.17) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 1.36e-08 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 95 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
0.14. 

Burst Advocate for this burst is P. D'Avanzo (paolo.davanzo 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: GRB171027A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22054
SUBJECT: GRB 171027A: Prompt enhanced Swift-XRT position
DATE:    17/10/27 09:16:01 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using  promptly downlinked XRT event data for GRB 171027A, we find an
enhanced XRT position of the afterglow: RA, Dec: 61.6907, -2.6223 which
is equivalent to:
   RA (J2000)  = 04 06 45.78
   Dec (J2000) = -02 37 20.4
with an uncertainty of 2.1 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at
http://www.swift.ac.uk/sper/783479.

Position enhancement is is described by Goad et al. (2007, A&A, 476,
1401) and Evans et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB171027A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22055
SUBJECT: GRB 171027A: MASTER-OAFA (Argentina) early prompt optical observations
DATE:    17/10/27 10:28:03 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, D.Kuvshinov, P.Balanutsa, 
A.Kuznetsov, V.V.Chazov, D. Vlasenko, I.Gorbunov, A.V.Krylov
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

R. Podesta, Carlos Lopez and F. Podesta
Observatorio Astronomico Felix Aguilar (OAFA)

Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias


K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk
Irkutsk State University

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

V. Yurkov, A. Gabovich, Yu. Sergienko
Blagoveschensk Educational State University, Blagoveschensk


D. Buckley, S. Potter, A. Kniazev, M. Kotze
South African Astronomical Observatory

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in OAFA was pointed to the  GRB171027A ( D'Avanzo et al., GCN 
Circ 22053 ) 26 sec after notice time 
and 71 sec after trigger time at 2017-10-27 08:24:17 UT. On our first (10s 
exposure)  set we haven't found optical transient  within SWIFT error-box 
(ra=61.6708 dec=-2.60556 r=0.05). The 5-sigma upper limit has been about 
17.5 mag . This and next 2 images  are prompt optical limit because GRB 
duration is ~ 120 
sec (D'Avanzo et al., GCN Circ 22053 )



The OT limit are:

   ID       UT     Exp          Type             Limit

103456  08:24:17   10      Alert (SWIFT)        17.5
103463  08:24:17   70   SumAlert (SWIFT)        19.0
103473  08:24:17  550   SumAlert (SWIFT)        20.0
103457  08:25:09   20      Alert (SWIFT)        18.1
103459  08:26:10   40    Alert (SWIFT) 18.6
103467  08:27:34  210   SumAlert (SWIFT)        19.5
103460  08:27:34   50      Alert (SWIFT)        18.6
103461  08:29:07   70      Alert (SWIFT)        18.9
103462  08:31:00   90      Alert (SWIFT)        19.0
103472  08:33:15  450   SumAlert (SWIFT)        19.9
103464  08:33:15  120      Alert (SWIFT)        19.2
103466  08:36:00  150      Alert (SWIFT)        19.2
103468  08:39:15  180      Alert (SWIFT)        19.3
103476  08:43:00  540   SumAlert (SWIFT)        19.5
103470  08:43:00  180      Alert (SWIFT)        19.0
103471  08:46:43  180      Alert (SWIFT)        18.8
103474  08:50:25  180      Alert (SWIFT)        18.4
103477  08:54:08  180      Alert (SWIFT)        18.1
103478  08:57:53  180      Alert (SWIFT)        18.1


The observations made on zenit distance = 41 degrees, galaxy latitude b = 
-37 degree. The moon (45 % bright part) below the horizon (The altitude of 
the Moon is -33 degree ). Observations started at twilight.
The sun  altitude  is -16.5 degree.
The object can be observed till sunrise at 2017-10-27 09:44:50


The message may be cited.


GRB_name: GRB171027A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22056
SUBJECT: GROND observations of GRB 171027A
DATE:    17/10/27 11:17:03 GMT
FROM:    Patricia Schady at MPE/Swift  <pschady@mpe.mpg.de>

P. Schady (MPE) reports:

Observations of the field of GRB 171027A (Swift trigger 783479; D'Avanzo
et al., GCN #22053) were carried out simultaneously in g'r'i'z' with GROND
(Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at
ESO La Silla Observatory (Chile).

Observations started at 08:51 UT on 27-10-2017, 28.4 mins after the GRB
trigger. They were performed during astronomical twilight, at an average
seeing of 1.4" and at an average airmass of 1.4.

Using a total exposure of 4.4 min, no source is detected within the 2.1"
enhanced Swift/XRT error circle (Evans et al., GCN 22054) down to the
following 3 sigma upper limits (all in AB):

g' > 23.1
r' > 23.1
i' > 22.3
z' > 22.2

Given magnitudes are calibration against PanSTARRS and are not corrected
for the expected Galactic foreground extinction corresponding to a
reddening of E_(B-V)=0.12 mag in the direction of the burst (Schlafly &
Finkbeiner 2011).

I acknowledge the excellent support provided by Angela Hempel in obtaining
these data.


GRB_name: GRB171027A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22057
SUBJECT: GRB 171027A: RATIR Detection of a NIR Afterglow Candidate 
DATE:    17/10/27 11:20:05 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>

Alan M. Watson (UNAM), Eleonora Troja (GSFC), Nat Butler (ASU),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer
(UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB),
Antonino Cucchiara (UVI), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz
(UCSC), JesÃºs GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey
Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki
Toy (UMD) report:

We observed the field of GRB 171027A (D'Avanzo et al., GCN Circ. 22053)
with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
AstronÃ³mico Nacional on Sierra San Pedro MÃ¡rtir from 2017/10 27.35 to
2017/10 27.37 UTC (0.04 to 0.51 hours after the BAT trigger), obtaining
a total of 0.36 hours exposure in the r and i bands and 0.15 hours
exposure in the Z, Y, J, and H bands.

For a source within the Swift-XRT error circle, in comparison with the
USNO-B1 and 2MASS catalogs, we obtain the following detections and upper
limits (3-sigma):

  r > 23.17
  i > 23.12
  Z > 20.66
  Y > 21.09
  J = 20.95 +/- 0.26
  H = 19.12 +/- 0.06

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. The source position is at RA,
Dec (J2000) = 04:06:45.77 -02:37:18.9 (+/- 0.5 arcsec). We currently
have no evidence for fading.

The very red colors suggest that this might be at high redshift or
dusty.

Further observations are planned.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB171027A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22058
SUBJECT: GROND observations of GRB 171027A: correction
DATE:    17/10/27 11:49:56 GMT
FROM:    Patricia Schady at MPE/Swift  <pschady@mpe.mpg.de>

P. Schady (MPE) reports:

The upper limits reported in GCN #22056 were in fact calibrated against
GROND zeropoints. The 3-sigma upper limits (AB) calibrated against
PanSTARRS are in fact:

g' > 22.2
r' > 22.2
i' > 21.2
z' > 21.0

The reported magnitudes are not corrected for the expected Galactic
foreground extinction corresponding to a reddening of E_(B-V)=0.12 mag in
the direction of the burst (Schlafly & Finkbeiner 2011).


GRB_name: GRB171027A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22059
SUBJECT: GRB 171027A: LCO 1-m telescope observations
DATE:    17/10/27 11:51:22 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell (U. Bath), 
A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU) on behalf of a large 
collaboration report:

We began observing Swift GRB171027A (D'Avanzo et al. GCN 22053) on 
October 27, from 08:39:29 to 09:06:37 UT (16 minutes since the GRB 
trigger time) with one of the 1-m LCO McDonald telescopes in the SDSS 
gri filters. Within the enhanced Swift-XRT error circle (Evans et al. 
22054) and in particular at the position of the NIR afterglow candidate 
(Watson et al. GCN 22057) we do not see any optical source down to the 
following limits in agreement with previous reports (Lipunov et al. GCN 
22055; Schady et al. GCN 22056):

Mid Time Exposure Filter Magnitude (AB)
(hrs) (s)
-------------------------------------------------------
0.5 5x60 SDSS-G > 19.5
0.5 5x60 SDSS-R > 19.3
0.5 5x60 SDSS-I > 18.8
-------------------------------------------------------

as calibrated against nearby USNO URAT1 objects.


GRB_name: GRB171027A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22060
SUBJECT: GRB 171027A: VLT optical upper limits
DATE:    17/10/27 12:01:58 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani (DARK/NBI), N. R. Tanvir (Univ. Leicester), P. Schady (MPE), 
A. de Ugarte Postigo (IAA/CSIC and DARK/NBI), K. E. Heintz (Univ. 
Iceland and DARK/NBI), G. Pugliese (API, Univ. Amsterdam), report on 
behalf of the Stargate collaboration:

We observed the field of GRB 171027A (D'Avanzo et al., GCN 22053) with 
the ESO Very Large Telescope (VLT) UT2 equipped with X-shooter. 
Observations started on 2017 Oct 27.379 UT (42.8 min after the trigger) 
using the acquisition camera, entirely during twilight. For this reason, 
only short exposures could be secured (45 s in r, 60 s in z).

Within the prompt-enhanced XRT position (Evans, GCN 22054) we find no 
new sources down to r > 23, z > 22.7 mag (all AB, calibrated against the 
Pan-STARRS catalog). Our results are consistent with the lack of optical 
detection by GROND (Schady, GCNs 22056, 22058), RATIR (Watson et al., 
GCN 22057), and LCO (Guidorzi, GCN 22059). In particular, we confirm 
that no object is visible at the position of the NIR candidate reported 
by Watson et al. (GCN 22057).

We acknowledge excellent support from the ESO staff, in particular 
Michael Hilker and Francisco Labrana.


GRB_name: GRB171027A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22061
SUBJECT: GRB 171027A: RATIR Confirmation of Fading and Photo-z
DATE:    17/10/27 14:50:03 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), JesÃºs
GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey Moseley (GSFC), John
Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:

We continued to observe the field of GRB 171027A (D'Avanzo et al., et al.,
GCN 22053) with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
AstronÃ³mico Nacional on Sierra San Pedro MÃ¡rtir from 2017/10 27.35 to
2017/10 27.53 UTC (0.04 to 4.24 hours after the BAT trigger), obtaining a
total of 2.82 hours exposure in the r and i bands and 1.18 hours exposure
in the Z, Y, J, and H bands.

At late time, the source is only detected in the H-band, with H = 19.12 +/-
0.06.  This magnitude is calibrated relative to 2MASS and is in the AB
system, not corrected for Galactic extinction in the direction of the GRB.
We measure a fade in the H-band flux in time as t^(-1.0+/-0.1).

Using all bands (see, Watson et al., GCN 22057), we find high A_V photo-z
solutions nearby (z<3.85, 90% conf.) and a high-z solution which assumes
A_V=0 (z=9+/-1).  We note that the XRT N_H constraints (D'Avanzo et al., et
al., GCN 22053) point toward the high A_V solution, although with low
statistical significance.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB171027A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22062
SUBJECT: GRB 171027A: Enhanced Swift-XRT position
DATE:    17/10/27 14:59:05 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 3587 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 171027A, 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 = 61.69071, -2.62207 which is equivalent
to:

RA (J2000): 04h 06m 45.77s
Dec (J2000): -02d 37' 19.5"

with an uncertainty of 1.4 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) and Evans
et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB171027A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22063
SUBJECT: GRB 171027A: Swift-XRT refined Analysis
DATE:    17/10/27 15:09:38 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

S. J. LaPorte (PSU), J.A. Kennea (PSU), A.P. Beardmore (U. Leicester),
P.A. Evans (U. Leicester), S.L. Gibson (U. Leicester), V. D'Elia
(ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti
(INAF-OAB/PSU) and P. D'Avanzo report on behalf of the Swift-XRT team:

We have analysed 6.8 ks of XRT data for GRB 171027A (D'Avanzo et al.
GCN Circ. 22053), from 81 s to 18.6 ks after the  BAT trigger. The data
comprise 191 s in Windowed Timing (WT) mode (the first 5 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Goad et al.
(GCN Circ. 22054).

The light curve can be modelled with an initial power-law decay with an
index of alpha=3.53 (+/-0.12), followed by a break at T+274 s to an
alpha of 0.96 (+/-0.03).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.43 (+/-0.07). The
best-fitting absorption column is  2.8 (+/-0.4) x 10^21 cm^-2, in
excess of the Galactic value of 1.1 x 10^21 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.02 (+0.13, -0.12)
and a best-fitting absorption column of 3.6 (+0.6, -0.5) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.8 x 10^-11 (5.8 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      3.6 (+0.6, -0.5) x 10^21 cm^-2
Galactic foreground: 1.1 x 10^21 cm^-2
Excess significance: 7.7 sigma
Photon index:      2.02 (+0.13, -0.12)

If the light curve continues to decay with a power-law decay index of
0.96, the count rate at T+24 hours will be 0.026 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.7 x
10^-13 (1.5 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00783479.

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


GRB_name: GRB171027A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22064
SUBJECT: GRB 171027A: Swift/UVOT Upper Limits
DATE:    17/10/28 10:59:30 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates (U. Warwick) and P. D'Avanzo (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 171027A
96 s after the BAT trigger (D'Avanzo et al., GCN Circ. 22053).
No optical afterglow consistent with the optical position
(Watson et al. GCN Circ. 22057)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            96          246          147         >20.6
u_FC               308          558          246         >20.0
white               96         6148          428         >21.2
v                  639         6558          432         >19.7
b                  564         5943          236         >20.3
u                  308         5737          462         >20.3
w1                 688         6835          282         >19.8
m2                5126         6763          393         >19.8
w2                4716         6354          393         >20.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.14 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB171027A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22066
SUBJECT: GRB 171027A, Swift-BAT refined analysis
DATE:    17/10/28 16:22:47 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), P. D'Avanzo (INAF-OAB),
H. A. Krimm (NSF/USRA), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-61 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 171027A (trigger #783479)
(D'Avanzo et al., GCN Circ. 22053).  The BAT ground-calculated position is
RA, Dec = 61.683, -2.601 deg which is
  RA(J2000)  =  04h 06m 43.8s
  Dec(J2000) = -02d 36' 02.0"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 91%.

The mask-weighted light curve shows a multi-peaked structure that starts
at ~T-2 s and ends at ~T+150 s. The main peak occurs at ~ T+63 s.
T90 (15-350 keV) is 96.6 +- 4.8 sec (estimated error including systematics).

The time-averaged spectrum from T-2.0 to T+132.0 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.25 +- 0.18,
and Epeak of 150.4 +- 95.1 keV (chi squared 33.21 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 7.5 +- 0.2 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+62.29 sec in the 15-150 keV band is
3.0 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.53 +- 0.04 (chi squared 40.62 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/783479/BA/


GRB_name: GRB171027A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22070
SUBJECT: Konus-Wind observation of GRB 171027A
DATE:    17/10/29 17:43:50 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 171027A (Swift-BAT trigger #783479: (D'Avanzo et al.,
GCN  22053; Lien et al., GCN 22066; T0(BAT)=08:23:06.623 UT)
was detected by Konus-Wind (KW) in the waiting mode.

The light curve shows a muli-peaked structure with a duration of ~103 s.
Modeling the KW 3-channel time-integrated spectrum
(from T0(BAT)-1.661 s to T0(BAT)+101.379 s) by
a power law with exponential cutoff (CPL) model
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.21(-0.35,+0.20) and Ep = 176(-35,+47) keV.
The energy fluence for this time interval is (1.78 Â± 0.21)x10^-5
erg/cm2, and the peak energy flux, measured on a 2.944 s scale from
T0(BAT)+63.107 s is (6.6 Â± 0.12)x10^-7 erg/cm2/s, both in the
20 keV-10 MeV range.

Assuming the GRB photo-z < 3.85 (90%, Butler et al., GCN 22061)
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.30, and Omega_Lambda = 0.70, our analysis sets
the following upper limits on the burst isotropic energy release
and rest-frame peak energy: E_iso < 5.2x10^53 erg and
Ep,z < 854 keV.

The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB171027A/

All the quoted errors are estimated at the 1 sigma confidence level.
All the presented results are preliminary.


GRB_name: GRB171022A
Detection_method: retraction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22071
SUBJECT: GRB 171022A: Fermi-LAT detection retraction
DATE:    17/10/30 20:24:53 GMT
FROM:    Elisabetta Bissaldi at U.Innsbruk/IAPP  <Elisabetta.Bissaldi@uibk.ac.at>

M. Palatiello (Univ & INFN Trieste), E. Bissaldi (Poiltecnico & INFN Bari),
and E. Moretti (MPI Munich) report on behalf of the Fermi-LAT team:


On October 22nd, 2017, the Fermi-LAT collaboration reported
the detection of GRB 171022A (Palatiello et al., GCN #22045).

Following the publication of the GRB IPN triangulation
(Hurley et al., GCN #22051), we performed further analysis to
investigate the discrepancy of the Fermi-LAT localization
with respect to the region defined by the Konus Wind,
Fermi-GBM and INTEGRAL annuli.

The LAT excess reported in Palatiello et al. has a
significance which is only slightly
above the 5 sigma threshold. Moreover, the Fermi-LAT
Point Source Catalog (3FGL, Acero et al. 2015) contains
the source 3FGL J1339.0+1153 in the proximity of the position
of the LAT excess. A likelihood analysis where the normalization
for 3FGL J1339.0+1153 is set as a free parameter of the fit
returns a marginal increase (20 +/- 15 %) in the flux
of that source, tentatively associated with
SDSS J133859.05+115316.7, and results in a non-detection of the
excess which we previously associated with GRB 171022A.
Therefore, we cannot confirm at this stage that
the LAT excess is associated with GRB 171022A.


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.


GRB_name: GRB171027A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22073
SUBJECT: GRB 171027A: KAIT Optical Upper Limit
DATE:    17/10/30 23:39:12 GMT
FROM:    Weikang Zheng at UC Berkeley  <weikang@berkeley.edu>

WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on
behalf of the KAIT GRB team:

The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, responded to Swift GRB 171027A (D'Avanzo et al.,
GCN 22053) starting at 08:26:07 UT, 181 s after the burst.
Observations were performed with an automatic sequence in the
clear (roughly R), V, and I filters, and the exposure time was 20 s
per image. We do not detect the optical source (Watson et al., GCN 22057;
Butler et al., GCN 22061) in our images. The typical limiting magnitude
of our single clear image is about 19.0 calibrated to USNO B1.0.


GRB_name: GRB171030A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22076
SUBJECT: IPN Triangulation of GRB 171030A (short)
DATE:    17/10/31 18:30:52 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and

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

A short-duration GRB 171030A has been detected by
Fermi (GBM trigger 531077390), INTEGRAL (SPI-ACS),
and Swift (BAT), so far, at about 62985 s UT (17:29:45).
The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
------------------------------------
   RA(2000), deg  Dec(2000), deg
------------------------------------
  Corners:
    47.7467      -25.6001
    37.3056      -48.8763
   117.4353      -11.9668
   118.1759      -5.9280
------------------------------------
The error box maximum dimension is 79.5 deg
(the minimum one is 5.9 deg).

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB171030_T62985/IPN

The time history and spectrum will be given in forthcoming GCN 
Circulars.


GRB_name: GRB171030A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22077
SUBJECT: GRB 171030A: Swift ToO observations
DATE:    17/10/31 23:41:14 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Swift has initiated a ToO observation of the Swift/BAT GRB 171030A. 
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020783

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Swift/BAT event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a 
GCN Circular after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

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

[GCN OPS NOTE(01nov17): Per author's request, the GRB name in the Subject-line
and in the first line has been changed from "1701030" to 171030A".


GRB_name: GRB171030A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22078
SUBJECT: GRB 171030A: Swift non-localization with BAT, XRT and UVOT
DATE:    17/11/01 17:13:59 GMT
FROM:    Valerio D'Elia at ASDC  <valerio.delia@ssdc.asi.it>

V. D'Elia (SSDC), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. Malesani (DARK/NBI), J.A. Kennea (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU) and P.A. Evans (U. Leicester) report on behalf of the Swift team:

At 17:29:45.12 UT on 2017-10-30, Swift BAT detected the rate increase associated with a short Fermi/GBM burst (Fermi trigger 531077390, BAT trigger #784509), also detected by INTEGRAL, and later broadly localized with the Interplanetary Network (IPN) using data from all three spacecraft (GCN # 22076).

On-board imaging found no sources above a 6.5 sigma image threshold, but ground analysis showed that a sub-threshold peak (5.8 sigma) in the image domain was consistent with the IPN error box and the Fermi/GBM 2 sigma localization. This image peak was about half the intensity that would be normally expected based on the count rate excess, but this is within the range of plausible variation allowed by statistics and systematics.  We also note that the IPN and Fermi localizations have a large fraction of their area outside of the BAT FOV, where BAT has rate-increase sensitivity but no localization ability.  Therefore, the data are consistent with locations both at the sub-threshold image peak, and outside of the FOV.

A Swift XRT ToO observation was requested for the purpose of determining whether there was an afterglow at the image peak location. The BAT on-board calculated location is  RA, Dec 68.671, -15.422 which is
RA(J2000) = 04h 34m 41.0s
Dec(J2000) = -15d 25 19.2"
with an uncertainty of 3 arcmin (radius, 90% containment).

Swift-XRT has performed follow-up observations of the Swift/BAT-detected burst GRB 171030A, collecting 4.0 ks of Photon Counting (PC) mode data between T0+108.9 ks and T0+127.0 ks.

No X-ray sources have been detected consistent with being within 296 arcsec of the Swift/BAT position. The 3-sigma upper limit in the field is 0.003 ct  s^-1, corresponding to a 0.3-10 keV observed flux of 1.2e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum).

Two uncatalogued sources were detected too far from the GRB position to be likely afterglow candidates.

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
http://www.swift.ac.uk/ToO_GRBs/00020783.

The Swift/UVOT observed the field of GRB 171030A three times between 109 ks and 116 ks after the trigger for a total exposure of 1751 s.  All the exposures used the UVW2 filter. No new source was found with an upper limit of 21.0 mag. No correction has been made  for the Galactic extinction due to the reddening of E(B-V) = 0.22 in the direction of the burst (Schlegel et al. 1998).

Based on the non-detection of an afterglow by XRT, we conclude that GRB 171030A was either outside of the BAT FOV, and thus not associated with the location of the sub-threshold image peak, or too faint to be detected at the time of the Swift ToO.

This is an official product of the Swift team.


GRB_name: GRB171030A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22079
SUBJECT: GRB 171030A: Fermi GBM detection
DATE:    17/11/01 21:29:07 GMT
FROM:    Rachel Hamburg at UAH  <rkh0007@uah.edu>

R. Hamburg (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 17:29:45.12 UT on 30 October 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171030A (trigger 531077390 / 171030729)
which was also detected by Swift/BAT and INTEGRAL/SPI-ACS, as reported
by the Interplanetary Network (GCN 22076). The GBM on-ground location is
consistent with the Swift/BAT location (GCN 22078).

The angle from the Fermi LAT boresight at the GBM trigger time is 135
degrees.

The GBM light curve shows a single peak
with a duration (T90) of about 0.1 s (50-300 keV).
The time-averaged spectrum from T0-0.06 s to T0+0.00 s is
adequately fit by a simple power law function with index -1.11 +/- 0.07.

The event fluence (10-1000 keV) in this time interval is
(1.7 +/- 0.2)E-07 erg/cm^2. The 0.064-sec peak photon flux measured
starting from T0-0.064 s in the 10-1000 keV band
is 11.6 +/- 2.2 ph/s/cm^2.

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


GRB_name: GRB171030A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22080
SUBJECT: GRB 171030A: IPN error box through NSs probability merging rate map
DATE:    17/11/02 08:17:37 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, 
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

D.Svinkin
Ioffe Institute, St Petersburg

E. Gorbovskoy, N.Tyurina, D.Kuvshinov
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University


We present NSs merging rate MAP inside local 50 Mpc distance (see 
Lipunov, V. M.; Nazin, S. N.; Panchenko, I. E.; Postnov, K. A.; 
Prokhorov, M. E. The gravitational wave sky, Astronomy and 
Astrophysics, v.298, p.677, 1995; Lipunov et al., 2017,
https://arxiv.org/ftp/arxiv/papers/1710/1710.05911.pdf ).

There are two common regions belong to IPN (Kozlova et al., GCN 22076) 
(black   on picture) aproximated next 
rectangle:

First:

  [37,-35]
  [60,-20]
  [60,-30]
  [40,-45]


Second:

[73,-10]
[80,-04]
[80,-11]
[73,-21]

Maps are available at
http://observ.pereplet.ru/images/VLNSmergrate.jpg

The possible Swift localisation () is shown by green square.


Common IPN + NSsMerging probability Map region are available

http://observ.pereplet.ru/images/GRB171030A_1.txt
http://observ.pereplet.ru/images/GRB171030A_2.txt

The message may be cited.


GRB_name: GRB171102A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22081
SUBJECT: GRB 171102A: Fermi-LAT detection
DATE:    17/11/02 15:00:44 GMT
FROM:    Manal Yassine at INFN,Trieste  <mychbib@gmail.com>

**M. Yassine (Univ & INFN Trieste), E. Bissaldi (Politecnico & INFN Bari)
and D. Kocevski (NASA/MSFC) report on behalf of the Fermi-LAT team:

At 2:33:35.99 UT on November 02, 2017, Fermi-LAT detected
high-energy emission from GRB 171102A,
which was also detected by Fermi-GBM (trigger 531282820).

The best LAT on-ground location is found to be

RA, Dec: 188.41, 53.63 (degrees, J2000)

with an error radius of 0.57 deg (90% containment, statistical error only).
This was 43 deg from the LAT boresight at the time of the trigger.

The data from the Fermi-LAT show a significant increase
in the event rate that is spatially and temporally correlated
with the GBM emission with high significance.

More than 17 photons above 100 MeV are observed within 500 seconds.
The highest-energy photon is a 500 MeV event which is
observed 328 seconds after the GBM trigger.

A Swift ToO has been requested for this burst. 

The Fermi-LAT point of contact for this burst is
Manal Yassine (mychbib@gmail.com).

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.

[GCN OPS NOTE(03nov17): Per author's request, the URL link to the Swift ToO page
and the URL link to gmail were removed.]

[GCN OPS NOTE(06nov17): Per author's request, intitutional affiliation
was corrected from INAF to INFN.]


GRB_name: GRB171102B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22082
SUBJECT: GRB 171102B: Swift detection of a burst
DATE:    17/11/02 15:37:07 GMT
FROM:    David Burrows at PSU/Swift  <burrows@astro.psu.edu>

T. N. Ukwatta (LANL), D. N. Burrows (PSU), A. D'Ai (INAF-IASFPA),
V. D'Elia (ASDC), Alex Deich (PSU), J.D. Gropp (PSU),
J. A. Kennea (PSU), H. A. Krimm (NSF/USRA), S. J. LaPorte (PSU),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester) and
M. H. Siegel (PSU) report on behalf of the Swift Team:

At 15:20:29 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 171102B (trigger=785510).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 288.103, +22.438 which is 
   RA(J2000) = 19h 12m 25s
   Dec(J2000) = +22d 26' 16"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 20 sec.  The peak count rate
was ~1500 counts/sec (15-350 keV), at ~4 sec after the trigger. 

The XRT began observing the field at 15:22:33.3 UT, 123.8 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 288.07776, 22.44512 which is equivalent
to:
   RA(J2000)  = 19h 12m 18.66s
   Dec(J2000) = +22d 26' 42.4"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 87 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.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 4.51
x 10^21 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 250 seconds with the U filter starting
124 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 18.0 mag. No correction has been made for the expected extinction
corresponding to E(B-V) of 0.75. 

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: GRB171102A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22083
SUBJECT: GRB 171102A: Fermi GBM detection
DATE:    17/11/02 15:51:46 GMT
FROM:    Matthew Stanbro at UAH/Fermi  <mcs0001@uah.edu>

M. Stanbro (UAH), C. Meegan (UAH), and E. Bissaldi (Politecnico & INFN Bari)
report on behalf of the Fermi GBM Team:

"At 02:33:35.99 UT on 02 November 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171102A (trigger 531282820 / 171102107)
which was also detected by the Fermi-LAT (M. Yassine et al. 2017, GCN 22081)
The GBM on-ground location is consistent with the LAT position.

The trigger resulted in an Autonomous Repoint Request (ARR)
by the GBM Flight Software owing to the high peak flux of the GRB.
This ARR was accepted and the spacecraft slewed to the GBM in-flight
location. The initial angle from the Fermi LAT boresight to
the LAT location is 43 degrees.

The GBM light curve shows multiple peaks
with a duration (T90) of about 35 s (50-300 keV).
The time-averaged spectrum from T0+20.48 s to T0+56.32 s is
best fit by a Band function with Epeak = 171 +/- 6 keV,
alpha = -0.82 +/- 0.02, and beta = -2.59 +/- 0.14.

The event fluence (10-1000 keV) in this time interval is
(2.88 +/- 0.05)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+49.2 s in the 10-1000 keV band
is 28.7 +/- 0.3 ph/s/cm^2.

A power law function with an exponential high-energy cutoff
fits the spectrum equally well.  The power law index is -0.87 +/- 0.02 and
the cutoff energy, parameterized as Epeak, is 187 +/- 4 keV.

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


GRB_name: GRB171102B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22084
SUBJECT: GRB 171102B: Enhanced Swift-XRT position
DATE:    17/11/02 19:08:46 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 1915 s of XRT Photon Counting mode data and 5 UVOT
images for GRB 171102B, 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 = 288.07787, +22.44433 which is equivalent
to:

RA (J2000): 19h 12m 18.69s
Dec (J2000): +22d 26' 39.6"

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) and Evans
et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB171102B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22085
SUBJECT: GRB 171102B: Swift-XRT refined Analysis
DATE:    17/11/03 00:06:36 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia
(ASDC), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), A. Tohuvavohu
(PSU) and T.N. Ukwatta report on behalf of the Swift-XRT team:

We have analysed 10 ks of XRT data for GRB 171102B (Ukwatta et al. GCN
Circ. 22082), from 110 s to 24.1 ks after the  BAT trigger. The data
comprise 7 s in Windowed Timing (WT) mode (taken while Swift was
slewing), with the remainder in Photon Counting (PC) mode. The enhanced
XRT position for this burst was given by Osborne et al. (GCN Circ.
22084).

The light curve can be modelled with an initial power-law decay with an
index of alpha=0.58 (+0.08, -0.11), followed by a break at T+5902 s to
an alpha of 1.32 (+0.43, -0.17).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.17 (+0.17, -0.16). The
best-fitting absorption column is  5.8 (+1.7, -1.3) x 10^21 cm^-2,
consistent with the Galactic value of 4.5 x 10^21 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 6.9 x 10^-11 (8.1 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      5.8 (+1.7, -1.3) x 10^21 cm^-2
Galactic foreground: 4.5 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.17 (+0.17, -0.16)

If the light curve continues to decay with a power-law decay index of
1.32, the count rate at T+24 hours will be 4.1 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.8 x
10^-13 (3.3 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00785510.

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


GRB_name: GRB171102B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22086
SUBJECT: GRB 171102B: Swift/UVOT Upper Limits
DATE:    17/11/03 05:32:40 GMT
FROM:    Sam LaPorte at PSU  <sjl5346@psu.edu>

GRB 171102B: Swift/UVOT Upper Limits

S. J. LaPorte (PSU) and T. N. Ukwatta (LANL)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 171102B
125 s after the BAT trigger (Ukwatta et al., GCN Circ. 22082).
No optical afterglow consistent with the XRT position
(Osborne et al. GCN Circ. 22084)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC          4979         5129          147         >20.2
u_FC               125          375          246         >19.8
white             4979         5749          344         >20.5
v                  432        11930         1160         >19.3
b                  381        18368         1057         >20.5
u                  125        24106         2391         >21.5
w1                 481        23421         2042         >20.7
m2                 456        22515         1843         >21.3
w2                 407        11017         1179         >20.7

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.75 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB171102B
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22087
SUBJECT: GRB 171102B: MITSuME Akeno optical upper limits
DATE:    17/11/03 12:12:39 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata@u.phys.nagoya-u.ac.jp>

S. Harita, R. Itoh, K. L. Muarata, Y. Tachibana, T. Yoshii, K. Morita, T.
Ozawa, H. Mamiya, K. Shiraishi, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB171102B (T. N. Ukwatta et
al., GCN Circular #22082) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of Akeno Observatory,
Yamanashi, Japan.

The observation started on 2017-11-03 09:05:03.04 UT . We did not find any
new point source within XRT circle in all three bands.

We obtained following limits for the magnitudes.

T0+[hour]    MID-UT      T-EXP[sec]         g'              Rc
 Ic
-------------------------------------------------------------------------------------------------------
~17.742       09:24:59           300          >18.2        >17.5
>16.9
-------------------------------------------------------------------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.


GRB_name: GRB171102B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22088
SUBJECT: GRB 171102B: Swift-BAT refined analysis
DATE:    17/11/03 13:03:02 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 171102B (trigger #785510)
(Ukwatta et al., GCN Circ. 22082).  The BAT ground-calculated position is
RA, Dec = 288.096, 22.434 deg which is
   RA(J2000)  =  19h 12m 23.0s
   Dec(J2000) = +22d 26' 03.2"
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 22%.

The mask-weighted light curve shows a weak pulse that starts at ~ T-6 s and
ends at ~ T+14 s. T90 (15-350 keV) is 17.8 +- 3.1 sec (estimated error including
systematics).

The time-averaged spectrum from T-6.18 to T+13.72 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.16 +- 0.24.  The fluence in the 15-150 keV band is 9.3 +- 1.4 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+3.51 sec in the 15-150 keV band
is 1.2 +- 0.4 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/785510/BA/


GRB_name: GRB171102B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22089
SUBJECT: GRB 171102B: RATIR Optical and NIR Observations
DATE:    17/11/03 15:04:13 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), JesÃºs
GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey Moseley (GSFC), John
Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:

We observed the field of GRB 171102B (Ukwatta, et al., GCN 22082) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on
Sierra San Pedro MÃ¡rtir from 2017/11 3.14 to 2017/11 3.20 UTC (11.99 to
13.55 hours after the BAT trigger), obtaining a total of 0.98 hours
exposure in the r and i bands and 0.42 hours exposure in the Z, Y, J, and H
bands.

For a source within the Swift-XRT error circle (Osborne, et al., GCN
22084), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the
following upper limits (3-sigma):

 r > 22.51
 i > 22.59
 Z > 21.14
 Y > 21.53
 J > 21.36
 H > 20.97

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.


GRB_name: GRB171102B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22090
SUBJECT: GRB 171102B: Nanshan 0.36m and 0.60m optical upper limits
DATE:    17/11/03 15:49:14 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

H.J. Tan (CCU), Z.P. Zhu, H.X. Feng, D. Xu (NAOC), Y.D. Hu (IAA-CSIC), 
X. Gao (Urumqi No.1 Senior High School) report:

We observed the field of GRB 171102B (Ukwatta et al., GCN 22082) using 
the 0.36m and 0.60m telescopes located at Nanshan, Xinjiang, China. All 
imaged were taken without filter.

Our photometry was summarized as follows:
========================================
Tmid(s)+T0  Telescope  Exptime(s)       UL(R)

389               36cm        40*3             >16.10

645               60cm        30*3             >17.80

1365             60cm        60*15           >18.55

========================================
Note: (1) Photometry is calibrated with stars (R2 magnitude) in the USNO 
B1 catalogue, although images were taken without filter.


GRB_name: GRB171102A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22091
SUBJECT: IPN Triangulation of GRB 171102A
DATE:    17/11/03 17:44:38 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and

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

The long-duration GRB 171102A (Yassine et al., GCN Circ. 22081; Stanbro 
et al., GCN Circ. 22083) was detected by Konus-Wind, Fermi (GBM trigger 
531282820), INTEGRAL (SPI-ACS), and Swift (BAT) at about 9216 s UT 
(02:33:36). The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3-sigma error box whose 
coordinates are:
---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   188.823 (12h 35m 18s) +54.288 (+54d 17' 15")
  Corners:
   180.299 (12h 01m 12s) +53.175 (+53d 10' 31")
   179.157 (11h 56m 38s) +54.095 (+54d 05' 41")
   197.995 (13h 11m 59s) +54.514 (+54d 30' 52")
   198.922 (13h 15m 41s) +53.378 (+53d 22' 41")
  ---------------------------------------------
The error box area is 11.5 sq. deg, and its maximum
dimension is 11.7 deg (the minimum one is ~1 deg).
The Sun distance was about 70 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB171102_T09247/IPN

The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.


GRB_name: GRB171102B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22092
SUBJECT: GRB 171102B: TShAO optical upper limit
DATE:    17/11/03 20:49:21 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI),  A. Kusakin (Fesenkov Astrophysical Institute), A. 
Pozanenko (IKI),  I. Reva (Fesenkov Astrophysical Institute),    A. 
Volnova (IKI)  report on behalf of larger GRB follow-up collaboration:

We observed the field of the Swift  GRB 170822A   (Ukwatta et al.,
GCN  22082) with Zeiss-1000 1-m telescope of Tien Shan Astronomical 
Observatory starting on Nov., 02 (UT) 15:47:45.  We took several images 
in R-filter.  Within enhanced XRT error circle  (Osborne et al., GCN 
22084) we do not detect  any  object.  Preliminary  photometry of the 
afterglow is following.

Date       UT start   t-T0    Filter Exp.  OT     Err. UL
                      (mid, days)     (s)             (3 sigma)


2017-11-02 15:47:45  0.04377  R    30*120  n/d    n/d  20.1


Photometry is based on nearby USNO-B1.0 stars R2 magnitudes
USNO-B.1_id  R2
1124-0422739 16.70
1124-0422527 16.20
1124-0422440 15.76


GRB_name: GRB171102B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22093
SUBJECT: GRB 171102B: AbAO optical upper limit
DATE:    17/11/03 20:51:02 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI),  R. Inasaridze (AbAO), A. Pozanenko (IKI),   A. 
Volnova  (IKI),   V. Ayvazian (AbAO),  O. Kvaratskhelia (AbAO), G. 
Inasaridze (AbAO), I. Molotov (KIAM) report on behalf of larger GRB 
follow-up  collaboration:

We observed the field of the Swift  GRB 170822A   (Ukwatta et al.,
GCN  22082) with AS-32 (0.7m) telescope of Abastumani Observatory 
starting on Nov., 02 (UT) 15:53:26. We obtained several unfiltered 
images of the field.   Within enhanced XRT error circle  (Osborne et 
al., GCN   22084) we do not detect  any  object.  Preliminary photometry 
of the field is following

Date        UT start  t-T0     Filter Exp.   OT   Err UpLim (3 sigma)
                       (mid, days)     (s)

2017-11-02 15:53:26   0.05497  CR     53*60  n/d  n/d 21.7

Photometry is based on nearby USNO-B1.0 stars R2 magnitudes
USNO-B.1_id  R2
1124-0422571 18.10
1124-0422577 17.52
1124-0422572 18.34
1124-0422730 17.80

A finding chart can be found at 
http://grb.rssi.ru/GRB171102B/GRB171102B_AAO_171102.png


GRB_name: GRB171102A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22094
SUBJECT: Konus-Wind observation of GRB 171102A
DATE:    17/11/03 22:18:16 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova@mail.ioffe.ru>

A. Tsvetkova, S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Lysenko, A. Kozlova and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration, intense GRB 171102A
(Fermi-LAT detection: Yassine et al., GCN 22081;
Fermi GBM detection: Stanbro et al., GCN 22083;
IPN Triangulation: Kozlova et al., GCN 22091)
triggered Konus-Wind at T0=9247.579 s UT (02:34:07.579).

The burst light curve shows two emission episodes
with a total duration of ~28 s.
The emission is seen up to ~1 MeV.

As observed by Konus-Wind, the burst
had a fluence of 2.96(-0.32,+0.27)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+14.608 s,
of 5.87(-0.95,+0.96)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+21.760 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.76(-0.11,+0.11),
the high energy photon index beta = -2.98(-3.40,+0.31),
the peak energy Ep = 174(-12,+16) keV,
chi2 = 90/97 dof.

The spectrum near the peak count rate
(measured from T0+8.448 to T0+16.128 s)
is best fit in the 20 keV - 1.2 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.91(-0.12,+0.12),
and Ep = 203(-17,+21) keV (chi2 = 56/60 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -2.52 (chi2 = 56/59 dof).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB171102_T09247/

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


GRB_name: GRB171103A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22095
SUBJECT: GRB 171103A: Swift detection of a short hard burst
DATE:    17/11/03 23:23:43 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

T. N. Ukwatta (LANL), A. D'Ai (INAF-IASFPA), V. D'Elia (ASDC),
Alex Deich (PSU), H. A. Krimm (NSF/USRA), N. P. M. Kuin (UCL-MSSL),
D. M. Palmer (LANL), M. H. Siegel (PSU) and A. Tohuvavohu (PSU) report
on behalf of the Swift Team:

At 23:10:32 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 171103A (trigger=785850).  Swift did not slew due to an 
observing constraint. 
The BAT on-board calculated location is 
RA, Dec 249.536, -10.215 which is 
   RA(J2000) = 16h 38m 09s
   Dec(J2000) = -10d 12' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of less than 1 sec.  The peak count rate
was ~20000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 11:32 UT on 2018 January 15. There will thus be no XRT
or UVOT data for this trigger before this time. 

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: GRB171010A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22096
SUBJECT: GRB 171010A: VLT spectroscopic identification of the associated SN 2017htp
DATE:    17/11/04 00:16:56 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (HETH/IAA-CSIC and DARK/NBI), J. Selsing (DARK/NBI), D. Malesani (DARK/NBI), D. Xu (NAOC/CAS), L. Izzo (HETH/IAA-CSIC), K. E. Heinz (Univ. Iceland and DARK/NBI), D. A. Kann (HETH/IAA-CSIC), G. Leloudas (DARK/NBI), S. Schulze (WIS), N. R. Tanvir (Univ. Leicester), S. Covino (INAF/Brera), P. D'Avanzo (INAF/Brera), J. P. U. Fynbo (DARK/NBI), D. Hartmann (Clemson Univ.), J. Hjorth (DARK/NBI), C. Kouveliotou (GWU), L. Kaper (API, Univ. Amsterdam), A. J. Levan (Univ. Warwick), A. Melandri (INAF/Brera), P. Moller (ESO), G. Pugliese (API, Univ. Amsterdam), B. Sbarufatti (INAF/Brera and PSU), and P. Schady (MPE), S. Schmidl (TLS), on behalf of the STARGATE collaboration, report:

We observed the optical counterpart of GRB 171010A (Omodei et al., GCN 21985; Poolakkil & Meegan, GCN 21992; Sharma et al., GCN 21990) at z = 0.33 (Kankare et al., GCN 22002) using the ESO Very Large Telescope. Imaging was secured on 2017 Oct 31.25 UT (20.45 days after the GRB) using the VIMOS instrument, in the R and I filters, for a total of 10 min exposure each.

Both the candidate host galaxy of the GRB (Thorstensen & Halpern, GCN 21897; Izzo & Malesani, GCN 21988) and a second compact source, at a location consistent with that of the optical afterglow, are well visible in our images. The spatial coincidence of the second source could indicate late-time emission associated with the GRB, or the presence of an underlying star-forming region.

Spectroscopy covering both the host nucleus and the afterglow location was carried out on 2017 Nov 1.25 UT (21.46 days after the GRB; 16 days in the GRB rest frame), using the X-shooter spectrograph, for a total exposure time of 4x1200 s. The traces of both objects are visible, showing a wealth of narrow nebular emission lines, some of which especially intense at the afterglow location. We measure for the galaxy nucleus a redshift z = 0.3285, consistent with the report by Kankare et al. (GCN 22002).

Faint continuum emission is detected at the GRB location. This could be due to an associated SN, as expected for long GRBs at this redshift, or to an underlying star forming region, or a combination of both. The spectral shape is curved and redder than at the nucleus location, but extinction is low as inferred from the Balmer decrement. This opens the possibility of excess light from the SN. In the attempt to isolate its contribution, we then estimated the host contamination by rescaling the nucleus spectrum assuming it contributes the entire flux at 3500 AA (rest frame), where GRB-associated SNe have negligible emission (e.g. Hjorth et al. 2003, Nature, 423, 847; Mazzali et al. 2003, ApJ, 599, 95), due to metal line blanketing.

By comparing the residual contribution with known SN/GRB templates, we find a good resemblance with other GRB-associated SNe, such as SN 1998bw (at 6 days post maximum; e.g. Patat et al. 2001, ApJ, 555, 900) and SN 2006aj (at 5 days post maximum; e.g. Pian et al., Nature, 442, 1011). Based on this resemblance, the object has been assigned the IAU name of SN 2017htp. The brightness of the SN is about 30% (1.3 mag fainter) than SN 1998bw at a comparable epoch. An accurate computation requires however a more rigorous host subtraction which will be possible with late-time templates.

A plot showing the spectra can be viewed at this URL:

https://wis-tns.weizmann.ac.il/system/files/uploaded/STARGATE/tns_2017htp_classrep_1386_STARGATE.png <https://wis-tns.weizmann.ac.il/system/files/uploaded/STARGATE/tns_2017htp_classrep_1386_STARGATE.png>

We acknowledge unfaltering support from the ESO staff at Paranal, in particular Marcelo Lopez, Juan Carlos Munoz, Nestor Jimenez, Eleonora Sani, Fernando Selman, and Romain Thomas.


GRB_name: GRB171103A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22099
SUBJECT: GRB 171103A: Swift-BAT refined analysis of a short GRB
DATE:    17/11/04 21:58:58 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC),  J. R. Cummings (CPI),
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
J. P. Norris (BSU), T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (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 171103A (trigger #785850)
(Ukwatta et al., GCN Circ. 22095).  The BAT ground-calculated position is
RA, Dec = 249.510, -10.206 deg which is
  RA(J2000)  =  16h 38m 02.4s
  Dec(J2000) = -10d 12' 22.9"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 65%.

The mask-weighted light curve shows a complex multi-peak structure.  It begins
with three peaks from -0.8 sec to +0.3 sec. This is followed by low-level, slowly
decaying emission out to ~T+20 sec and then a weaker peak at ~T+60 sec. The
spacecraft slewed away from the burst location at ~T+600 sec due to a
pre-planned slew. T90 (15-350 keV) is 3.90 +- 1.11 sec (estimated error
including systematics).

The time-averaged spectrum from T-0.37 to T+4.67 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.31 +- 0.18.  The fluence in the 15-150 keV band is 3.8 +- 0.4 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-0.37 sec in the 15-150 keV band
is 3.6 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The duration and hardness of this burst show it to be intermediate between the
short and long burst populations. Using a 8-ms binned light curve, the lag analysis
finds a lag of -0.5 +/- 4 ms for the 100-350 keV to 25-50 keV band, and -0.7 +/- 5 ms
for the 50-100 keV to 15-25 keV band. These values are consistent with those of
a short GRB.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/785850/BA/


GRB_name: GRB171103A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22100
SUBJECT: GRB 171103A: Fermi GBM observation
DATE:    17/11/05 16:12:21 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P Veres (UAH) reports on behalf of the Fermi GBM Team:

"
GRB 171103A, detected by Swift (Ukwatta et al, GCN #22095) is clearly
visible in the GBM data. It was not possible for GBM to trigger at
this time because GBM was still in trigger mode for a transient that
occurred 190 s earlier (171103963 / 531443246).

The angle from the Fermi LAT boresight at the Swift trigger time is
102 degrees.

The GBM light curve shows a single pulse with a duration (T90) of
about 1.1 s (50-300 keV). The time-averaged spectrum for a 0.4 s
interval starting from 23:10:31.951 UT is best fit by a power law
function with an exponential high-energy cutoff.  The power law index
is -0.74 +/- 0.05 and the cutoff energy, parameterized as Epeak, is
2.1 +/- 0.2 MeV.

The event fluence (10-1000 keV) in this time interval is
(2.7 +/- 0.1)E-6 erg/cm^2. The 64-ms peak photon flux measured
starting from 23:10:32.082 in the 10-1000 keV band is
30.3 +/- 2.0 ph/s/cm^2.

"


GRB_name: GRB171103A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22101
SUBJECT: Konus-Wind observation of GRB 171103A (short/hard)
DATE:    17/11/05 20:11:39 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova@mail.ioffe.ru>

A. Tsvetkova, S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Lysenko, A. Kozlova and T. Cline
on behalf of the Konus-Wind team, report:

The short-duration, hard-spectrum, intense GRB 171103A
(Swift detection of a short hard burst: Ukwatta et al., GCN 22095;
Palmer et al., GCN 22099;
Fermi GBM observation: Veres, GCN 22100)
triggered Konus-Wind at T0=83429.176 s UT (23:10:29.176).

The burst light curve shows a single pulse with a total duration of ~0.3 s.
The emission is seen up to ~15 MeV.

As observed by Konus-Wind, the burst
had a fluence of 8.50(-1.47,+1.57)x10^-6 erg/cm2,
and a 16-ms peak energy flux, measured from T0-0.030 s,
of 7.12(-2.18,+2.26)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+0.256 s)
is best fit in the 20 keV - 15 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.76(-0.17,+0.20),
and Ep = 2463(-690,+1054) keV (chi2 = 31/28 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -1.98 (chi2 = 31/27 dof).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB171103_T83429/

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


GRB_name: GRB171030A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22102
SUBJECT: GRB 171030A: MASTER inspection of the IPN error box of the short GRB.
DATE:    17/11/06 12:01:21 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, D.Kuvshinov, 
P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko, I.Gorbunov, A.V.Krylov
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

D.Svinkin
Ioffe Institute, St Petersburg

R. Podesta, Carlos Lopez and F. Podesta
Observatorio Astronomico Felix Aguilar (OAFA)

Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias

K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk
Irkutsk State University

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

V. Yurkov, A. Gabovich, Yu. Sergienko
Blagoveschensk Educational State University, Blagoveschensk

D. Buckley, S. Potter, A. Kniazev, M. Kotze
South African Astronomical Observatory


GRB171030A was detected by Fermi (Hamburg  and C. Meegan, GCN 22079) at 
17:29:45.12 UT on 30 October 2017. This is was slightly soft short GRB can be 
off-axis gamma emission produced by near (<50-100 Mpc) mergin Neutron Stars 
(Burgess et al., Viewing short Gamma-ray Bursts from a different angles, 
arXiv:1710.05823, https://arxiv.org/abs/1710.05823 ).


MASTER Robotic Net inspected IPN error box (Kozlova et al., GCN 22076) and its 
common parts with NSs merging rate MAP inside local 50 Mpc distance (see 
Lipunov, V. et al., GCN 22080 ).
MASTER-OAFA, MASTER-IAC, MASTER-Tunka, MASTER-Kislovodsk and MASTER-SAAO 
covered 99% of the full IPN error box 
(1248 square degrees).
The common region of the NSs merging rate MAP inside local 50 Mpc distance and 
IPN has 112 square degrees and 256 square degrees correspondingly.
The avarage upper limit during this inspection was 18.5. The best limit 
was 19.5, worst was 18.0.

The coverage map is available at
https://master.sai.msu.ru/site/master2/ligo_one.php?id=10072

  We  found 3  OTs:

1). MASTER OT J031444.34-471210.0 detection - New Dwarf Nova (Lipunov et 
al., ATel 
- 10928).

MASTER-OAFA auto-detection system ( <A 
HREF="http://www.hindawi.com/journals/aa/2010/349171/">Lipunov et al., "MASTER 
Global Robotic Net", Advances in Astronomy, 2010, 30L</A> )
  discovered OT source at (RA, Dec) = 03h 14m 44.34s -47d 12m 10.0s on 
2017-11-03.21736 UT.

The OT unfiltered magnitude is 17.1m (mlim=18.6m).

The discovery and reference images are available at

http://master.sai.msu.ru/static/OT/031444.34-471210.0.png


2) MASTER OT J034515.40-015216.5 detection - CSS 090219:034515-015216 U Gem + 
Ursae Majoris Type Variables  at  outburst .

MASTER-IAC auto-detection system discovered OT source at
(RA, Dec) = 03h 45m 15.40s -01d 52m 16.5s on 2017-10-31.14317 UT.
The OT B magnitude is 14.6m (limit 18.3m), R magnitude is 14.4 .

We have reference unfiltered images on
2015-12-03 00:28:33.686 m_OT=19.5
2016-08-15 05:24:15.584 m_OT=19.3
2017-03-15 20:57:59.196 m_OT=19.6.

This OT is also known as CSS UGSU 
http://www.aavso.org/vsx/index.php?view=detail.top&oid=193659

The discovery and reference images are available at:

http://master.sai.msu.ru/static/OT/034515.40-015216.5.png

3). MASTER OT J034412.48-263556.5 discovery - PSNIa before maximum   in 
0"W,21"S of  PGC134086 galaxy

MASTER-OAFA auto-detection system ( <A 
HREF="http://www.hindawi.com/journals/aa/2010/349171/">Lipunov et al., "MASTER 
Global Robotic Net", Advances in Astronomy, 2010, 30L</A> )
  discovered OT source at (RA, Dec) = 03h 44m 12.48s -26d 35m 56.5s on 
2017-11-06.23799 UT.


The OT unfiltered magnitude is 18.7m (mlim=18.7m). 
This OT(PSN) is  in 0"W,21"S of PGC134086  (Btc=16.2, V_GSR,LG=19958km/s, 
http://leda.univ-lyon1.fr/ledacat.cgi?PGC134086)_B=-21.1+-0.9 
). The galaxy distance is aboute 300 Mpc.



There are 5 images with PSN:


2017-11-06 05:27:16UT

2017-11-06 05:42:42UT

2017-11-06 07:34:52UT

2017-11-06  07:38:38UT

2017-11-06 07:42:22UT

We have reference images without OT on 2017-09-27.19196 UT with unfiltered 
magnitude limit 20.1m, on <b> 2017-11-03 06:18:44</b> with mlim=17.7.  It   gives 
possibility to be a young PSN before maximum.

Spectral observations are required.

The only third optical transient  MASTER OT J034412.48-263556.5 is 
potentially 
can be connected with collapse processes produce fast rotating NS (see 
Lipunov, V.M.,2017,  Double O-Ne-Mg  white dwarfs merging as the source of the 
powerfull gravitational waves  for LIGO/VIRGO type interferometers, New 
Astronomy, Volume 56, p. 84-85). But it is very bright and
very late  for Kilonova after 30 October 2017 NSs merging.


Maps are available at
http://observ.pereplet.ru/images/VLNSmergrate.jpg

The possible Swift localisation (D'Elia etal.,  GCN 22078 ) is shown by green 
square. Its optical limit is 19.5 (unfiltered and B) and 18.0 (I) between 
2017-10-31 22:43:33 UT and  2017-11-01  02:37:44 UT


Common IPN + NSsMerging probability Map two regions are available

http://observ.pereplet.ru/images/GRB171030A_1.txt
http://observ.pereplet.ru/images/GRB171030A_2.txt

The message may be cited.


GRB_name: GRB171103A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22103
SUBJECT: GRB 171103A: AstroSat CZTI detection
DATE:    17/11/06 12:52:32 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:

Analysis of Astrosat CZTI data showed the detection of a short bright GRB 171103A, which was also detected by Swift-BAT (Ukwatta T. N. et al, GCN # 22095), Fermi-GBM (Veres P., GCN # 22100) and Konus-Wind (Tsvetkova A. et al, GCN # 22101).

The source was clearly detected in the 40-200 keV energy range. The light curve shows single peak of emission with peak at 23:10:32.100 UT. The measured peak count rate is 1420.9 cts/s above the background in combined data of four quadrants, with a total of 2964 cts. The local mean background count rate was 349.1 cts/s. Using cumulative rates, we measure a T90 of 0.46 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB171010A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22107
SUBJECT: GRB 171010A: possible SN component
DATE:    17/11/07 00:01:02 GMT
FROM:    Antonino Cucchiara at UVI  <antonino.cucchiara@uvi.edu>

A. Cucchiara (University of the Virgin Islands),
L. G. Strolger (STScI) report on  behalf of a larger
collaboration:

We observed the location of the LAT GRB 171010A (Omodei et al.,
GCN 21985; Poolakkil & Meegan, GCN 21992; Sharma et al.,
GCN 21990) at z = 0.33 (Kankare et al., GCN 22002) with the
1.3 m Remotely Controlled Telescope (RCT) located at Kitt Peak
Observatory in optical R-band. We performed a series of 120s
exposures under good conditions (2.2 arcseconds seeing) and
airmass of 1.4 on average.

Beginnng October 23.41 UT (12.21 days post burst) we identified
an excess over the host galaxy flux and a subsequent fading optical
source at the location of the GRB+Host galaxy. These are indicative
of a possible supernova component (as suggested by de Ugarte Postigo
et al. GCN 22096).

T-T0          R Mag
(days)        (Host+SN)
12.21         18.87 +- 0.10
14.21         19.64 +- 0.13
15.21         20.21 +- 0.19

The magnitude are calibrated agains several USNO-B1 objects in
the field and are not corrected for galactic extinction.
Further observations are planned.
We thank the RCT Consortium for permitting these observations.
RCT is operated by South Carolina State University, Villanova
University, and University of Western Kentucky.


GRB_name: GRB171030A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22108
SUBJECT: GRB 171030A: MASTER OT J034412.48-263556.5 featureless continuum spectrum from  Lijiang 2.4m (China) telescope  and 2m the Himalayan Chandra
DATE:    17/11/08 08:41:18 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

Xiaofeng Wang
Physics Department and Tsinghua Center for Astrophysics, Tsinghua 
University, Beijing, 100084, China;

Jujia Zhang
Yunnan Observatories, Chinese Academy of Sciences,Kunming, 650011, China

Sahu D.K.
Indian Institute of Astrophysics

Lipunov V.,  Tiurina N., Gorbovskoy E.,
Lomonosov Moscow State SU, SAI


MASTER OT J034412.48-263556.5 (Lipunov et al., ATEL #10929 ; Lipunov et 
al. GCN #22102) was observed at  Lijiang 2.4m telescope for this 
transient, which shows blue and featureless continuum  like that 
of GRB170817A (Kilonova) but much brighter.
   We used YFOSC+G3 to  get the spectrum.

The second Spectrum was taken at 2-m aperture optical-infrared telescope, 
the Himalayan Chandra Telescope (HCT) with HFOSC (Hanle Faint Object 
Spectrograph Camera  https://www.iiap.res.in//iao/hfosc.html ) at Indian 
Astronomical Observatory https://www.iiap.res.in//iao/iao.html

The authors are grateful to prof. S.I.Blinnikov for comments.

Follow up observations are required.

The message may be cited.


GRB_name: GRB171101A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22110
SUBJECT: GRB 171101A CALET Gamma-Ray Burst Monitor detection
DATE:    17/11/09 00:31:16 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

T. Sakamoto, A. Yoshida, Y. Kawakubo, M. Moriyama, Y. Yamada,
A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu,
T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 171101A (INTEGRAL SPI-ACS trigger #7954) triggered the
CALET Gamma-ray Burst Monitor (CGBM) at 10:49:47.91 on 1 November 2017.
The burst signal was seen by the all CGBM instruments.

The light curve of the SGM shows a single peak.  The emission starts at T+3 sec,
peaks at T+4.5 sec and ends at T+15 sec.  The T90 duration measured by the
SGM data is 6.0 +- 0.4 sec (40-1000 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1193568506/index.html

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB171102A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22111
SUBJECT: GRB 171102A CALET Gamma-Ray Burst Monitor detection
DATE:    17/11/09 00:46:12 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

Y. Kawakubo, A. Yoshida, T. Sakamoto, M. Moriyama, Y. Yamada,
A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu,
T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 171102A (Yassine et al., GCN circ. 21615;
Stanbro et al., GCN circ. 22083; Kozlova et al., GCN circ. 22091;
Tsvetkova et al., GCN circ. 22094; INTEGRAL SPI-ACS trigger #7955) triggered
the CALET Gamma-ray Burst Monitor (CGBM) at 02:33:36.14 on 2 November 2017.
The burst signal was seen by the all CGBM instruments.  Because of a problem
in one of the ground alert processing script, the GCN notice was not distributed
automatically for this event.

The light curve of the SGM shows a complex structure with a precursor around
T0.  The precursor emission starts at T-2 sec and ends at T+2 sec.  The main burst
episode starts at T+30 sec, peaks at T+48 sec and ends at T+60 sec.  The T90
duration measured by the SGM data is 21.9 +- 0.3 sec (40-1000 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1193625133/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB171108A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22112
SUBJECT: GRB 171108A: Fermi GBM detection
DATE:    17/11/09 05:41:13 GMT
FROM:    Rachel Hamburg at UAH  <rkh0007@uah.edu>

R. Hamburg (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 15:44:46.50 UT on 8 November 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171108A (trigger 531848691 / 171108656).
The on-ground calculated location, using the GBM trigger
data, is RA = 115.0, DEC = +39.8 (J2000 degrees,
equivalent to 07 h 40 m, 39 d 48'), with an uncertainty
of 4.7 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg
systematic error. [Connaughton et al. 2015, ApJS, 216, 32]).

Although this GRB is soft in nature, the trigger resulted in an
Autonomous Repoint Request (ARR) by the GBM Flight Software
owing to high peak flux in the background before trigger time.
This ARR was accepted and the spacecraft slewed to the GBM in-flight
location. The initial angle from the Fermi LAT boresight to
the best GBM ground location is 84 degrees.

The GBM light curve shows a bright peak
with a duration (T90) of about 0.03 s (50-300 keV).
The time-averaged spectrum from T0-0.064 s to T0+0.064 s is
adequately fit by a power law function with an exponential
high-energy cutoff and a blackbody. The power law index is -1.6 +/- 0.4,
the cutoff energy, parameterized as Epeak, is 47 +/- 28 keV,
and the temperature is 18.0 +/- 3.0 kT.

The event fluence (10-1000 keV) in this time interval is
(1.0 +/- 0.1)E-05 erg/cm^2. The 0.064-sec peak photon flux measured
starting from T0-0.064 s in the 10-1000 keV band
is 687 +/- 166 ph/s/cm^2.

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


GRB_name: GRB171010A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22113
SUBJECT: GRB 171010A: afterglow and SN 2017htp optical observations
DATE:    17/11/09 15:51:55 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), A. Pozanenko (IKI),  V. Rumyantsev (CrAO), E. Klunko 
(ISTP),  I. Reva (Fesenkov Astrophysical Institute), A. Kusakin 
(Fesenkov Astrophysical Institute), O. Burhonov (UBAI), A. Volnova (IKI) 
   report on behalf of larger GRB follow-up collaboration:

We observed the field of the Fermi-LAT GRB 171010A (Omodei et al., GCN  
21985) with Zeiss-1000 telescope  (TSHAO), AZT-33IK telescope (Mondy), 
ZTSH2.6m telescope  (CrAO) and AZT-22 telescope  (Maidanak).
Within the enhanced Swift-XRT circle (D'Ai et al., GCN 21989) we clearly 
detect the optical afterglow (Thorstensen & Halpern , GCN 21987; Izzo & 
D. Malesani, GCN 21988; Guidorzi et al., GCN 21991; Malesani et al., GCN 
22000; Harita et al., GCN 22001; Kankare et al., GCN 22002; Breeveld & 
Siegel, GCN 22004; Watson et al., GCN 22011; Kumar et al., GCN 22012).

Still not all data received and we report some preliminary photometry 
of the afterglow in earlier epochs and host+OT in R-filter:

Date       UT_start   t-T0       OT     Err.    Up.Lim.   Telescope
            (mid, days)                          (3 sigma)
2017-10-12 20:11:03  2.11360     19.06  0.04    22.4      Zeiss-1000
2017-10-13 18:34:36  3.00616     19.21  0.05    22.2      AZT-33IK
2017-10-14 18:23:31  3.99492     19.38  0.03    23.1      AZT-33IK
2017-10-15 18:23:04  4.99461     19.35  0.03    23.0      AZT-33IK
2017-10-20 00:57:51  9.26249     19.60  0.03    23.4      ZTSH2.6
2017-10-28 19:42:20 18.04966     19.50  0.06    22.8      AZT-33IK
2017-11-06 19:44:54 27.07226     20.00  0.10    21.4      AZT-22

The photometry is based on nearby USNO-B1.0 stars

USNO-B.1_id     R2
0795-0045061    15.10
0795-0045035    17.25
0795-0045066    16.59

A light curve of the OT+host can be found in 
http://grb.rssi.ru/GRB171010A/GRB171010A_light_curve_R.png

As can be seen from the light curve we can support discovery of  SN 
2017htp (de Ugarte Postigo et al., GCN 22096; Cucchiara et al., GCN 22107).
We will update the LC as more data becomes available.


GRB_name: GRB171103A
Detection_method: Insight-HXMT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22116
SUBJECT: GRB 171103A: Insight-HXMT observation
DATE:    17/11/10 07:57:17 GMT
FROM:    Shaolin Xiong at IHEP  <xiongsl@ihep.ac.cn>

G. Li, J. Y. Liao, S. L. Xiong, C. K. Li, X. B. Li, C. Z. Liu,
X. F. Li, Z. W. Li, X. F. Lu, Z. Chang, J. L. Zhao, A. M. Zhang,
C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU),
F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:

During the commissioning phase, at 2017-11-03T23:10:32.04 (T0),
Insight-HXMT/HE detected GRB 171103A (trigger ID: HEB171103965)
in a routine search of the data,which is also detected by
Swift/BAT (Ukwatta et al.,GCN 22095), Fermi/GBM (Veres et al., GCN 22100),
Konus-Wind (Tsvetkova et al.,GCN 22101) and AstroSat/CZTI
(Sharma et al., GCN 22103).

The Insight-HXMT light curve mainly consists of multi-pulses
with a duration (T90) of 0.21 s measured from T0+0.033 s.
The 10-ms peak rate, measured from T0+0.096 s, is 19946.0 cnts/sec.
The total counts from this burst is 2915.7 counts.

URL_LC: http://www.hxmt.org/images/GRB/HEB171103965_lc.jpg

All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.

The time-averaged spectrum from T0+0.05 s to T0+0.30 s is
adequately fit by a Power Law model with spectral index = -0.97 Â± 0.07.
The energy fluence is (4.1 Â± 0.3)e-6 erg/cm^2 in 200 - 5000 keV
in this time interval.

The analysis results presented above are preliminary;
final results will be published elsewhere.

Insight-HXMT is the first Chinese space X-ray telescope, which was funded
jointly by the China National Space Administration (CNSA) and the Chinese
Academy of Sciences (CAS). More information could be found at:
http://www.hxmt.org/index.php/enhome .


GRB_name: GRB171108A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22117
SUBJECT: IPN Triangulation of GRB 171108A (short)
DATE:    17/11/10 18:40:14 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team, and

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

The short-duration GRB 171108A (Hamburg and Meegan, GCN Circ. 22112) was 
detected by Fermi (GBM trigger 531848691), Konus-Wind, and Swift (BAT) 
at about 56686 s UT (15:44:46).
The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   109.952 (07h 19m 48s) +29.091 (+29d 05' 28")
  Corners:
   112.518 (07h 30m 04s) +45.785 (+45d 47' 05")
   107.816 (07h 11m 16s) +12.385 (+12d 23' 05")
   107.666 (07h 10m 40s) +12.387 (+12d 23' 12")
   112.309 (07h 29m 14s) +45.789 (+45d 47' 21")
  ---------------------------------------------
The error box area is 4.9 sq. deg, and its maximum
dimension is 33.6 deg (the minimum one is 8.8 arcmin).
The Sun distance was 116 deg.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB171108_T56686/IPN

The Konus-Wind time history and spectrum will be given a forthcoming GCN 
Circular.


GRB_name: GRB171112A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22118
SUBJECT: GRB 171112A: MAXI/GSC detection
DATE:    17/11/13 09:56:35 GMT
FROM:    H. Negoro at Nihon U.  <negoro@phys.cst.nihon-u.ac.jp>

GRB 171112A: MAXI/GSC detection

S. Sugita (Tokyo Tech), H. Negoro (Nihon U.), S. Nakahira (RIKEN), 
S. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara, N. Isobe, R. Shimomukai (JAXA),
T. Mihara, M. Sugizaki, W. Iwakiri, M. Shidatsu, F. Yatabe, Y. Takao, M. Matsuoka (RIKEN), 
N. Kawai, T. Yoshii, Y. Tachibana, S. Harita, Y. Muraki, K. Morita (Tokyo Tech), 
A. Yoshida, T. Sakamoto, M. Serino, Y. Kawakubo, Y. Kitaoka, T. Hashimoto (AGU), 
H. Tsunemi, T. Yoneyama (Osaka U.), 
M. Nakajima, T. Kawase, A. Sakamaki (Nihon U.),
Y. Ueda, T. Hori, A. Tanimoto, S. Oda, T. Morita, S. Yamada (Kyoto U.), 
Y. Tsuboi, R. Sasaki, Y. Nakamura, H. Kawai (Chuo U.), 
M. Yamauchi, C. Hanyu, K, Hidaka (Miyazaki U.), 
T. Kawamuro (NAOJ), 
K. Yamaoka (Nagoya U.) 

The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source 
at 20:50:01 UT on 2017 November 12. 
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (20.467 deg, -59.678 deg) = (01 21 52, -59 40 40) (J2000) 
with a statistical 90% C.L. elliptical error region 
with long and short radii of 0.17 deg and 0.12 deg, respectively. 
The roll angle of long axis from the north direction is 107.0 deg counterclockwise. 
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).

We estimated a rectangular error box for the transient source with the following corners
which were independently calculated with respect to each camera.
camera 2:
(20.320, -61.117) deg = (01 21 16, -61 07 01) (J2000)
(19.513, -61.013) deg = (01 18 03, -61 00 47) (J2000)
(21.134, -58.662) deg = (01 24 32, -58 39 42) (J2000)
(21.890, -58.756) deg = (01 27 33, -58 45 23) (J2000)
camera 7:
(19.831, -60.456) deg = (01 19 19, -60 27 20) (J2000)
(19.396, -60.398) deg = (01 17 35, -60 23 51) (J2000)
(20.488, -58.842) deg = (01 21 57, -58 50 31) (J2000)
(20.905, -58.897) deg = (01 23 37, -58 53 48) (J2000)
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).

The X-ray flux averaged over the scan was 437 +- 44 mCrab
(4.0-10.0keV, 1 sigma error).
There was no significant excess flux in the previous transit at UT 19:14
and in the next transit at UT 22:19:10 with an upper limit of 20 mCrab for each.


GRB_name: GRB171108A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22119
SUBJECT: Konus-Wind observation of GRB 171108A
DATE:    17/11/13 19:17:41 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

A.Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

The short-duration, soft-spectrum GRB 171108A
(Fermi GBM detection: Hamburg et al., GCN 22112;
IPN triangulation: Svinkin et al., GCN 22117)
triggered Konus-Wind at T0=56686.93 s UT (15:44:46.930).

The burst light curve shows a single pulse
which starts at T0-22 ms and has a total duration of ~30 ms.

As observed by Konus-Wind, the burst
had a fluence of 2.73(-0.38,+0.48)x10^-7 erg/cm2,
and a 16-ms peak flux, measured from T0-0.016 s,
of 1.25(-0.23,+0.27)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

Since the most intense part of the burst was detected before
the trigger, the spectral analysis was performed using
the KW 3-channel light curve data.

Modeling the KW 3-channel time-integrated spectrum
(from T0-0.022 s to T0+0.008 s)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = 0.86 (-1.20,+4.43), and Ep = 115 (-20,+30) keV.

Fitting this spectrum by a blackbody function
yields kT = 26.6 (-3.3, +4.3) keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB171108_T56686/

The burst is not seen in the waiting mode data.

All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.


GRB_name: GRB171112A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22121
SUBJECT: Konus-Wind observation of GRB 171112A
DATE:    17/11/14 14:23:53 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, A. Tsvetkova, A. Lysenko, A.Kozlova, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration GRB 171112A
(MAXI/GSC detection: Sugita et al., GCN Circ. 22118)
triggered Konus-Wind at T0=75019.162 s UT (20:50:19.162).

The burst light curve shows multipeaked structure
which starts at ~T0-204 s and has a total duration of ~310 s.
The emission is seen up to ~2 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB171112_T75019/

As observed by Konus-Wind, the burst
had a fluence of 1.80(-0.33,+0.47)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+0.720 s,
of 2.43(-0.97,+1.17)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+16.640 s)
is best fit in the 30 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.51(-0.30,+0.38),
the high energy photon index beta = -2.67(-1.20,+0.44),
the peak energy Ep = 200(-30,+34) keV
(chi2 = 91/82 dof).

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


GRB_name: GRB171112A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22123
SUBJECT: GRB 171112A: Fermi GBM Detection
DATE:    17/11/14 21:46:06 GMT
FROM:    Matthew Stanbro at UAH/Fermi  <mcs0001@uah.edu>

M. Stanbro, R. Hamburg, and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 20:50:17.15 UT on 12 November 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171112A (trigger 532212622 / 171112868)
which was also detected by the MAXI/GSC (Sugita et al. 2017, GCN 22118)
The GBM on-ground location is consistent with the MAXI position.

The angle from the Fermi LAT boresight at the GBM trigger time is 99
degrees.

The GBM light curve consists of multiple episodes
with a duration (T90) of about 145 s (50-300 keV).
The time-averaged spectrum from T0-45.44 s to T0+104.07 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.49 +/- 0.06 and
the cutoff energy, parameterized as Epeak, is 198 +/- 38 keV.

The event fluence (10-1000 keV) in this time interval is
(1.75 +/- 0.06)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.73 s in the 10-1000 keV band
is 6.50 +/- 0.31 ph/s/cm^2.

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


GRB_name: GRB171115A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22124
SUBJECT: GRB 171115A: Swift detection of a burst
DATE:    17/11/15 19:05:41 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

B. Sbarufatti (PSU), D. N. Burrows (PSU), A. Deich (PSU),
J.D. Gropp (PSU), J. A. Kennea (PSU), H. A. Krimm (NSF/USRA),
S. J. LaPorte (PSU), A. Y. Lien (GSFC/UMBC),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL), M. H. Siegel (PSU) and A. Tohuvavohu (PSU) report
on behalf of the Swift Team:

At 18:51:20 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 171115A (trigger=790053).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 278.413, +9.128 which is 
   RA(J2000) = 18h 33m 39s
   Dec(J2000) = +09d 07' 42"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 50 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 18:52:30.0 UT, 69.2 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source with an enhanced position: RA, Dec
278.3885, 9.1250 which is equivalent to:
   RA(J2000)  = 18h 33m 33.23s
   Dec(J2000) = +09d 07' 29.9"
with an uncertainty of 2.3 arcseconds (radius, 90% containment). This
location is 87 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 2.97
x 10^21 cm^-2 (Willingale et al. 2013). 

The initial flux in the 2.5 s image was 7.83e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White 
filter  starting 76 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 0.23. 

Burst Advocate for this burst is B. Sbarufatti (bxs60 AT 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: GRB171115A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22125
SUBJECT: GRB 171115A: Enhanced Swift-XRT position
DATE:    17/11/15 22:20:41 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 434 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 171115A, 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 = 278.38820, +9.12510 which is equivalent
to:

RA (J2000): 18h 33m 33.17s
Dec (J2000): +09d 07' 30.4"

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) and Evans
et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB171115A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22126
SUBJECT: GRB 171115A: Swift-XRT refined Analysis
DATE:    17/11/16 02:36:25 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), P. D'Avanzo
(INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), D.N. Burrows
(PSU), A. Tohuvavohu (PSU), S. J. LaPorte (PSU), A.P. Beardmore (U.
Leicester) and B. Sbarufatti report on behalf of the Swift-XRT team:

We have analysed 7.5 ks of XRT data for GRB 171115A (Sbarufatti et al.
GCN Circ. 22124), from 62 s to 18.4 ks after the  BAT trigger. The data
comprise 35 s in Windowed Timing (WT) mode (the first 6 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Beardmore
et al. (GCN Circ. 22125).

The light curve can be modelled with an initial power-law decay with an
index of alpha=3.81 (+0.26, -0.23), followed by a break at T+289 s to
an alpha of 0.46 (+0.10, -0.11).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.92 (+0.33, -0.23). The
best-fitting absorption column is  3.3 (+1.7, -0.3) x 10^21 cm^-2,
consistent with the Galactic value of 3.0 x 10^21 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 4.0 x 10^-11 (5.7 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      3.3 (+1.7, -0.3) x 10^21 cm^-2
Galactic foreground: 3.0 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.92 (+0.33, -0.23)

If the light curve continues to decay with a power-law decay index of
0.46, the count rate at T+24 hours will be 6.4 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.5 x
10^-13 (3.6 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00790053.

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


GRB_name: GRB171115A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22127
SUBJECT: GRB 171115A: Swift-BAT refined analysis
DATE:    17/11/16 04:11:47 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

T. Sakamoto (AGU), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), B. Sbarufatti (PSU)
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(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 171115A (trigger #790053)
(Sbarufatti et al., GCN Circ. 22124).  The BAT ground-calculated position is
RA, Dec = 278.392, 9.118 deg which is
  RA(J2000)  =  18h 33m 34.2s
  Dec(J2000) = +09d 07' 06.4"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The mask-weighted light curve shows a weak pulse that starts at ~T-7 s,
peaks at ~T-1 s, and ends at ~T+35 s. T90 (15-350 keV) is 38.2 +- 3.4 sec
(estimated error including systematics).

The time-averaged spectrum from T-7.38 to T+34.78 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.76 +- 0.18.  The fluence in the 15-150 keV band is 6.9 +- 0.8 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-2.32 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/790053/BA/


GRB_name: GRB171115A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22128
SUBJECT: GRB 171115A: MITSuME Akeno optical upper limits
DATE:    17/11/16 12:32:45 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata@u.phys.nagoya-u.ac.jp>

K. Morita, R. Itoh, K. L. Murata, T. Yoshii, Y. Tachibana, S. Harita, T.
Ozawa, H. Mamiya, K. Shiraishi, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 171115A (B. Sbarufatti et
al., GCN Circular #22124) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of Akeno Observatory,
Yamanashi, Japan.

The observation started on 2017-11-16 08:54:06 UT. We did not find any new
point source within enhanced XRT circle (A.P. Beardmoreet al., GCN Circular
#22125) in all three bands.

We obtained following limits for the magnitudes.

T0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic
-------------------------------------------------------------------------------------------------------
~14.05       09:14:00.87     2220     >19.6     >18.6     >18.1
-------------------------------------------------------------------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.


GRB_name: GRB171115A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22129
SUBJECT: GRB 171115A: MITSuME Okayama optical upper limits
DATE:    17/11/16 12:36:01 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata@u.phys.nagoya-u.ac.jp>

K. Morita, R. Itoh, K. L. Murata, T. Yoshii, Y. Tachibana, S. Harita, T.
Ozawa, H. Mamiya, K. Shiraishi, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 171115A (B. Sbarufatti et
al., GCN Circular #22124) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of Okayama Astrophysical
Observatory, Japan.

The observation started on 2017-11-16 08:59:56 UT. We did not find any new
point source within enhanced XRT circle (A.P. Beardmoreet al., GCN Circular
#22125) in all three bands.

We obtained following limits for the magnitudes.

T0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic
-------------------------------------------------------------------------------------------------------
~14.15       09:52:13.20     5100     >18.1     >17.5     >17.8
-------------------------------------------------------------------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.


GRB_name: GRB171115A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22130
SUBJECT: GRB 171115A: RATIR Optical and NIR Observations
DATE:    17/11/16 15:12:51 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), JesÃºs
GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey Moseley (GSFC), John
Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:

We observed the field of GRB 171115A (Sbarufatti, et al., GCN 22124) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on
the 1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional
on Sierra San Pedro MÃ¡rtir from 2017/11 16.08 to 2017/11 16.15 UTC (7.14 to
8.66 hours after the BAT trigger), obtaining a total of 1.07 hours exposure
in the r and i bands and 0.38 hours exposure in the Z, Y, J, and H bands.

For a source within the Swift-XRT error circle (Beardmore, et al., GCN
22125), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the
following upper limits (3-sigma):

 r > 23.05
 i > 23.19
 Z > 21.86
 Y > 21.66
 J > 21.13
 H > 20.71

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB171108B
Detection_method: Insight-HXMT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22131
SUBJECT: GRB 171108B: Insight-HXMT detection
DATE:    17/11/17 03:43:48 GMT
FROM:    Shaolin Xiong at IHEP  <xiongsl@ihep.ac.cn>

Q. Zhang, S. L. Xiong, X. B. Li, C. K. Li, C. Z. Liu, X. F. Li,
Z. W. Li, Z. Chang, X. F. Lu, J. L. Zhao, A. M. Zhang, Y. F. Zhang,
C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU),
F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:

During the commissioning phase, at 2017-11-08T06:42:24.00 (T0),
Insight-HXMT/HE detected GRB 171108B (trigger ID: HEB171108279)
in a routine search of the data. No other observation for this GRB has
been reported yet.

The Insight-HXMT/HE light curve mainly consists of a single pulse
with a duration (T90) of 3.6 s measured from T0-0.069 s.
The 500-ms peak rate, measured from T0+0.070 s, is 2084.5 cnts/sec.
The total counts from this burst is 4667.5 counts.

URL_LC: http://www.hxmt.org/images/GRB/HEB171108279_lc.jpg

All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.

The analysis results presented above are preliminary;
final results will be published elsewhere.

Insight-HXMT is the first Chinese space X-ray telescope, which was funded
jointly by the China National Space Administration (CNSA) and the Chinese
Academy of Sciences (CAS). More information about it could be found at:
http://www.hxmt.org/index.php/enhome .


GRB_name: GRB171120A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22133
SUBJECT: GRB 171120A: Swift detection of a burst
DATE:    17/11/20 13:34:57 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

A. Tohuvavohu (PSU), A. D'Ai (INAF-IASFPA), A. Deich (PSU),
P. A. Evans (U Leicester), J.D. Gropp (PSU), A. Y. Lien (GSFC/UMBC)
and K. L. Page (U Leicester) report on behalf of the Swift Team:

At 13:20:02 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 171120A (trigger=791201).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 163.787, +22.450 which is 
   RA(J2000) = 10h 55m 09s
   Dec(J2000) = +22d 26' 58"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 60 sec.  The peak count rate
was ~17000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 13:21:31.0 UT, 88.5 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source with an enhanced position: RA, Dec 163.7911,
22.4584 which is equivalent to:
   RA(J2000)  = 10h 55m 09.87s
   Dec(J2000) = +22d 27' 30.3"
with an uncertainty of 2.5 arcseconds (radius, 90% containment). This
location is 33 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.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data does not constrain the column density. 

The initial flux in the 2.5 s image was 2.00e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 98 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
0.02. 

Burst Advocate for this burst is A. Tohuvavohu (aaronb AT swift.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: GRB171115B
Detection_method: Insight-HXMT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22134
SUBJECT: GRB 171115B: Insight-HXMT detection
DATE:    17/11/20 13:54:54 GMT
FROM:    Shaolin Xiong at IHEP  <xiongsl@ihep.ac.cn>

Q. Zhang, S. L. Xiong, X. B. Li, C. K. Li, C. Z. Liu, X. F. Li,
Z. W. Li, Z. Chang, X. F. Lu, J. L. Zhao, A. M. Zhang, Y. F. Zhang,
C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU),
F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:

During the commissioning phase, at 2017-11-15T05:13:14.70 (T0),
Insight-HXMT/HE detected GRB 171115B (trigger ID: HEB171115217)
in a routine search of the data. No other observation for this GRB has
been reported yet.

The Insight-HXMT light curve mainly consists of a single pulse
with a duration (T90) of 1.78 s measured from T0+0.23 s.
The 500-ms peak rate, measured from T0+0.30 s, is 948.2 cnts/sec.
The total counts from this burst is 1295.0 counts.

URL_LC: http://www.hxmt.org/images/GRB/HEB171115217_lc.jpg

All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.

The analysis results presented above are preliminary;
final results will be published elsewhere.

Insight-HXMT is the first Chinese space X-ray telescope, which was funded
jointly by the China National Space Administration (CNSA) and the Chinese
Academy of Sciences (CAS). More information about it could be found at:
http://www.hxmt.org/index.php/enhome .


GRB_name: GRB171120A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22135
SUBJECT: GRB 171120A: Enhanced Swift-XRT position
DATE:    17/11/20 19:15:06 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 2976 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 171120A, 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 = 163.79042, +22.45869 which is equivalent
to:

RA (J2000): 10h 55m 9.70s
Dec (J2000): +22d 27' 31.3"

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) and Evans
et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB171120A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22136
SUBJECT: GRB 171120A: Fermi-LAT detection
DATE:    17/11/20 20:39:29 GMT
FROM:    Giacomo Vianello at SLAC  <giacomov@slac.stanford.edu>

F. Longo (University and INFN, Trieste), G. Vianello (Stanford),
D. Kocevski (NASA/GSFC) and M.Arimoto (Waseda University)

report on behalf of the Fermi-LAT collaboration:

At 13:20:02 on November 20, 2017, Fermi-LAT detected high-energy emission
from GRB 171120A,which was also detected by Swift-BAT (Tohuvavohu et al.,
GCN 22133) and by Fermi-GBM (trigger 532876807/171120556).

The best LAT on-ground location is found to be

RA, Dec = 163.84, 22.40 deg (J2000)

with an error radius of 0.17 deg (90% containment, statistical error only).

This was 24 deg from the LAT boresight at the time of the trigger.

The LAT on-ground position is consistent with the Swift-XRT localization (Evans
et al., GCN 22135).

More than 30 photons above 100 MeV are observed within ~ 6.5 ks seconds of
the trigger.  The highest-energy photon is a 3.4 GeV event which is observed
~4.8 ks seconds after the GBM trigger.

The Fermi-LAT point of contact for this burst is:

Francesco Longo (francesco.longo@ts.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.


GRB_name: GRB171120A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22137
SUBJECT: GRB 171120A: Swift-XRT refined Analysis
DATE:    17/11/20 21:49:56 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

K.L. Page (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A.
Melandri (INAF-OAB), A. Tohuvavohu (PSU), S. J. LaPorte (PSU), J.A.
Kennea (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester)
and  report on behalf of the Swift-XRT team: report on behalf of the
Swift-XRT team:

We have analysed 8.2 ks of XRT data for GRB 171120A, from 78 s to 22.5
ks after the  BAT trigger. The data comprise 337 s in Windowed Timing
(WT) mode (the first 9 s were taken while Swift was slewing) with the
remainder in Photon Counting (PC) mode. 

The late-time light curve (from T0+3.9 ks) can be modelled with a
power-law decay with a decay index of alpha=0.41 (+/-0.09).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.78 (+0.15, -0.14). The
best-fitting absorption column is  2.34 (+0.28, -0.26) x 10^22 cm^-2,
in excess of the Galactic value of 1.2 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.92 (+/-0.18) and a
best-fitting absorption column of 2.4 (+/-0.3) x 10^22 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 6.6 x 10^-11 (1.4 x 10^-10) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.4 (+/-0.3) x 10^22 cm^-2
Galactic foreground: 1.2 x 10^20 cm^-2
Excess significance: 12.8 sigma
Photon index:      1.92 (+/-0.18)

If the light curve continues to decay with a power-law decay index of
0.41, the count rate at T+24 hours will be 0.059 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.9 x
10^-12 (8.3 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00791201.

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


GRB_name: GRB171120A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22138
SUBJECT: GRB 171120A: Fermi GBM Detection
DATE:    17/11/21 00:44:27 GMT
FROM:    Matthew Stanbro at UAH/Fermi  <mcs0001@uah.edu>

M. Stanbro, C. Meegan, (UAH) and A von Kienlin (MPE)
report on behalf of the Fermi GBM Team:

"At 13:20:02.37 UT on 20 November 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171120A (trigger 532876807 / 171120556)
which was also detected by the Swift/BAT (A. Tohuvavohu et al. 2017, GCN
22133)
and Fermi LAT (F. Longo et al. 2017, GCN 22136).
The GBM on-ground location is consistent with the Swift position.

The trigger resulted in an Autonomous Repoint Request (ARR)
by the GBM Flight Software owing to the high peak flux
of the GRB. This ARR was accepted and the spacecraft slewed to the GBM
in-flight
location.

The GBM light curve consists of 2 pulses
with a duration (T90) of about 44 s (50-300 keV).
The time-averaged spectrum from T0+0.002 s to T0+44.897 s is
best fit by a Band function with Epeak = 141 +/- 12 keV,
alpha = -0.91 +/- 0.06, and beta = -2.16 +/- 0.09.

The event fluence (10-1000 keV) in this time interval is
(1.80 +/- 0.05)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.10 s in the 10-1000 keV band
is 35.69 +/- 0.51 ph/s/cm^2.

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


GRB_name: GRB171120A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22139
SUBJECT: GRB 171120A: Swift-BAT refined analysis
DATE:    17/11/21 04:19:31 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
A. Tohuvavohu (PSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 171120A (trigger #791201)
(Tohuvavohu et al., GCN Circ. 22133).  The BAT ground-calculated position is
RA, Dec = 163.774, 22.461 deg which is
   RA(J2000)  =  10h 55m 05.8s
   Dec(J2000) = +22d 27' 38.2"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 14%.

The mask-weighted light curve shows a multi-peaked structure that starts
at ~T-15 s and ends at ~T+65 s. The two main peaks occur at ~T0 and ~T+40 s,
respectively. T90 (15-350 keV) is 64 +- 16 sec (estimated error including
systematics).

The time-averaged spectrum from T-15.53 to T+64.47 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.06 +- 0.28,
and Epeak of 86.0 +- 19.0 keV (chi squared 55.57 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 8.6 +- 0.3 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+39.97 sec in the 15-150 keV band is
11.4 +- 0.5 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.67 +- 0.06 (chi squared 70.86 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/791201/BA/


GRB_name: GRB171120A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22140
SUBJECT: GRB 171120A: MITSuME Akeno optical upper limits
DATE:    17/11/21 10:18:12 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata@u.phys.nagoya-u.ac.jp>

H. Mamiya, R. Itoh, K. L. Murata, T. Yoshii, Y. Tachibana, S. Harita, K.
Morita, T. Ozawa, K. Shiraishi, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 171120A (A. Tohuvavohu et
al., GCN Circular #22133) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of Akeno Observatory,
Yamanashi, Japan.

The observation started on 2017-11-20 15:38:32.17 UT. We did not find any
new point source within enhanced XRT circle (P.A. Evans al., GCN Circular
#22135) in all three bands.

We obtained following limits for the magnitudes.

T0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic
------------------------------------------------------------------------------------------------------
~3.26       18:40:07.63     9960     >21.5     >20.7     >19.8
------------------------------------------------------------------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.


GRB_name: GRB171120A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22141
SUBJECT: GRB171120A: GWAC-F60A upper limit 
DATE:    17/11/21 11:39:32 GMT
FROM:    L.P. Xin at NAOC  <xlp@nao.cas.cn>

L. P. Xin,   W. L. Dong, P. P. Zhang,  X. H. Han, J. Y. Wei,   E. W. Liang, 
X. G. Wang, Y. J. Xiao,   Y. G. Yang,  X. M. Lu,  L. Huang,    H. B. Cai,   
X. M. Meng,   Y. L. Qiu,  Y. Xu, Y. J. Xiao, Y. T. Zheng, R. S. Zhang,  J. Wang,    
C. Wu,   J. S. Deng, D. W. Xu,  T. Damien and H. L. Li  report:

We  observed  GRB 171120A (Tohuvavohu et al., GCN 22133)   with
GWAC-F60A 60cm optical telescope at 19:06:58 UT,  Nov. 20th 2017, 
about 5.75  hours after the burst. 

No any new source  was  not detected in the XRT error circle 
(Evens et al., GCN 22135) in our 15*300 sec stacked R-band  image  
down to the 3 sigma  limit  of  about 19.5 mag at the mid time  of 6.25 hours 
after the burst. The brightness was calibrated by  USNO B1.0 R2 catalogues.

GWAC-F60A is operated by Guangxi university and NAOC, CAS, 
at Xinglong observatory, China.

The message may be cited.


GRB_name: GRB171120A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22142
SUBJECT: Konus-Wind observation of GRB 171120A
DATE:    17/11/21 12:48:30 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 171120A (Swift/BAT detection: Tohuvavohu et al., GCN 22133; 
Stamatikos et al., GCN 22139; Fermi-LAT detection: Longo et al.,
GCN 22136; Fermi-GBM detection: Stanbro et al., GCN 22138)
triggered Konus-Wind at T0=48000.683 s UT (13:20:00.683).

The KW light curve shows two separate emission episodes.
A total duration of the burst is ~44 s.
The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst had a fluence of
1.7(-0.3,+0.5)x10^-5 erg/cm2 and a 64-ms peak energy flux,
measured from T0+1.644, of (1.29 Â± 0.13)x10^-5 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+49.408 s)
is best fit in the 20 keV - 15 MeV range by a cutoff power-law
(CPL) function with the following model parameters:
the photon index alpha = -1.59(-0.19,+0.23),
and the peak energy Ep = 200(-56,+183) keV,
chi2 = 84/98 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep, and an upper limit on beta of -2.0.

The spectrum near the peak count rate (measured from T0+0.128
to T0+0.256 s) is best fit in the 20 keV - 15 MeV range by
the CPL function with the following model parameters:
the photon index alpha = -0.33(-0.30,+0.35),
and the peak energy Ep = 305(-41,+53) keV,
chi2 = 39/36 dof.
Fitting this spectrum with the GRB (Band) function yields
similar alpha and Ep, and an upper limit on beta of -2.7.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB171120_T48000/

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.


GRB_name: GRB171120A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22143
SUBJECT: GRB 171120A: AstroSat CZTI detection
DATE:    17/11/21 21:06:13 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:
 
Analysis of Astrosat CZTI data showed the detection of GRB 171120A, which was also detected by Swift-BAT (Tohuvavohu et al., GCN 22133), Fermi-GBM (trigger 532876807/171120556) and Fermi-LAT (Longo F. et al., GCN 22136).
 
The source was clearly detected in the 40-200 keV energy range. The light curve of the CZT detector shows a single peak of emission at 13:20:02 UT. The measured peak count rate is 367.4 cts/s above the background in combined data of four quadrants, with a total of 634 cts. The local mean background count rate was 307.6 cts/s. Using cumulative rates, we measure a T90 of 6.8 s. 
 
It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The Veto light curve shows a strong peak coincident with the peak in the CZT detector and a weaker second peak ~39 s later. 
 
CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB171120A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22144
SUBJECT: GRB 171120A: Swift/UVOT Upper Limits
DATE:    17/11/21 21:21:20 GMT
FROM:    Jeffrey Gropp at PSU  <jdg44@psu.edu>

J. D. Gropp (PSU) and A. Tohuvavohu (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 171120A
99 s after the BAT trigger (Tohuvavohu et al., GCN Circ. 22133).
No optical afterglow consistent with the refined XRT position
(Evans et al. GCN Circ. 22135)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            99          249          147         >19.9
u_FC               311          561          246         >19.7
white               99         5989          560         >21.1
v                  640         6399          413         >19.1
b                  566         5784          413         >20.9
u                  311        11713          811         >20.7
w1                5174        11532         1082         >21.0
m2                9724        10624          886         >21.0
w2                4559         6194          393         >21.0

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB171120A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22145
SUBJECT: GRB 171120A: Xinglong-2.16m optical upper limit
DATE:    17/11/22 04:24:59 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

Z.P. Zhu, H.X. Feng, D. Xu (NAOC), Y. Zhao, F. Xiao (NAOC), S.B. Qian 
(YNAO), Y.D. Hu (IAA-CSIC) report

We observed the field of GRB 171120A (Tohuvavohu et al., GCN 22133) 
using the 2.16-m telescope located at Xinglong, Hebei, China, equipped 
with BFOSC. We obtained 1x600s and 2x900s R-band frames, starting at 
18:54:02 UT on 2017-11-20, i.e., 5.57 hr after the BAT trigger.

No optical source was detected in the stacked image at the XRT position 
(Evens et al., GCN 22135), down to the limiting magnitude of R~21.5 mag 
at the median time of 5.95 hr post-burst, calibrated with the SDSS field.


GRB_name: GRB171119A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22146
SUBJECT: IPN Triangulation of GRB 171119A (long)
DATE:    17/11/22 09:41:43 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova,
and T. Cline on behalf of the Konus-Wind team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team, and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

The long-duration GRB 171119A was detected by
Fermi (GBM trigger 532828112), Konus-Wind, INTEGRAL (SPI-ACS),
and Mars-Odyssey (HEND) at about 85707 s UT (23:48:27).

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   135.318 (09h 01m 16s) -50.281 (-50d 16' 53")
  Corners:
   136.349 (09h 05m 24s) -52.250 (-52d 14' 59")
   134.356 (08h 57m 26s) -48.624 (-48d 37' 25")
   134.404 (08h 57m 37s) -48.273 (-48d 16' 21")
   136.374 (09h 05m 30s) -51.905 (-51d 54' 19")
  ---------------------------------------------
The error box area is 1893 sq. arcmin, and its maximum
dimension is 4.17 deg (the minimum one is 8.2 arcmin).
The Sun distance was 80 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB171119_T85705/IPN/

The time history and spectrum will be given in forthcoming
GCN Circulars.


GRB_name: GRB171119A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22147
SUBJECT: Konus-Wind observation of GRB 171119A
DATE:    17/11/22 10:09:22 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 171119A (IPN Triangulation: Hurley et al., GCN 22146)
triggered Konus-Wind at T0=85705.835 s UT (23:48:25.835)

The burst light curve shows a multi-peaked structure
with a total duration of ~33 s.
The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst had a fluence of
(4.6 Â± 0.5)x10^-5 erg/cm2 and a 64-ms peak energy flux,
measured from T0+5.248, of (1.7 Â± 0.2)x10^-5 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+39.936 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.84 (-0.09,+0.09),
the high energy photon index beta = -2.71 (-0.69,+0.27),
the peak energy Ep = 232 (-19,+22) keV,
chi2 = 94/97 dof.

The spectrum near the peak count rate (measured from T0+0.256 s
to T0+5.632 s) is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.55 (-0.12,+0.16),
the high energy photon index beta = -2.33 (-0.22,+0.17),
the peak energy Ep = 255 (-33,+32) keV,
chi2 = 122/97 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB171119_T85705/

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.


GRB_name: GRB171123A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22148
SUBJECT: GRB 171123A: Swift detection of a burst
DATE:    17/11/23 14:54:37 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P. A. Evans (U Leicester), D. N. Burrows (PSU), A. Deich (PSU),
J.D. Gropp (PSU), J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
M. H. Siegel (PSU) and A. Tohuvavohu (PSU) report on behalf of the
Swift Team:

At 14:14:47 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 171123A (trigger=791922).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 186.190, +32.531 which is 
   RA(J2000) = 12h 24m 46s
   Dec(J2000) = +32d 31' 51"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 40 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 14:16:17.8 UT, 90.2 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
possible X-ray source with an enhanced position: RA, Dec 186.2425, 32.5032
which is equivalent to:
   RA(J2000)  = 12h 24m 58.19s
   Dec(J2000) = +32d 30' 11.4"
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This
location is 188 arcseconds from the BAT onboard position, just outside the
BAT error circle. This possible source is weak and at the edge of the
region of the XRT which is promptly downlinked; we are not completely
certain that this is an astrophysical object. We are awaiting the full
dataset to confirm the nature of this source. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.90 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 9.4
(+9.50/-2.54) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 93 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 0.02. 

Burst Advocate for this burst is P. A. Evans (pae9 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: GRB171120A
Detection_method: Insight-HXMT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22149
SUBJECT: GRB 171120A: Insight-HXMT detection
DATE:    17/11/23 15:03:23 GMT
FROM:    Zhengwei Li at IHEP  <lizw@ihep.ac.cn>

Z. W. Li, J. Y. Liao, C. K. Li, X. B. Li, S. L. Xiong, C. Z. Liu, 
X. F. Li, Z. Chang, X. F. Lu, J. L. Zhao, A. M. Zhang, Y. F. Zhang,
C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU),
F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:

During the commissioning phase, at 2017-11-20T13:20:02.00 (T0),
Insight-HXMT detected GRB 171120A (trigger ID: HEB171120555)
in a routine search of the data, which was also observed by
Swift/BAT (A. Tohuvavohu et al, GCN Circ.22133), Swift/XRT(P.A. Evans 
et al, GCN Circ.22135),Fermi/GBM(M.Stanbro et al, GCN Circ.22138),


Fermi/LAT(F. Longo et al, GCN Circ.22136), Konus-Windan(D.Frederiks

et al, GCN Circ.22142) and AstroSat/CZTI (V.Sharma et al, GCN Circ.22143).




The Insight-HXMT light curve consists of two pulses with a duration (T90)

of 39.9s measured from T0+0.5s. The 200-ms peak rate, measured from 

T0+0.6s, is 6895.7 cnts/sec. The total counts from this burst is 5746.9 

counts.


URL_LC: http://www.hxmt.org/images/GRB/HEB171120555_lc.jpg

All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.



The time-averaged spectrum from T0-0.2 to T0+1.0 s is adequately fit by 

a Power Law model with spectral index = -1.96 +/- 0.07 . The energy fluence

is (6.20 +/- 0.33) E-06 erg/cm^2 in 200 - 5000 keV in this time interval.




The analysis results presented above are preliminary; final results will 

be published elsewhere.


Insight-HXMT is the first Chinese space X-ray telescope, which was funded
jointly by the China National Space Administration (CNSA) and the Chinese
Academy of Sciences (CAS). More information about it could be found at:
http://www.hxmt.org/index.php/enhome .


GRB_name: GRB171123A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22150
SUBJECT: GRB 171123A: Enhanced Swift-XRT position
DATE:    17/11/23 15:57:18 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 1128 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 171123A, 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 = 186.24641, +32.50104 which is equivalent
to:

RA (J2000): 12h 24m 59.14s
Dec (J2000): +32d 30' 03.7"

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) and Evans
et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB171123A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22151
SUBJECT: GRB 171123A: Confirmation of the X-ray afterglow
DATE:    17/11/23 16:41:02 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

We have now received the full dataset from the early Swift-XRT
observations of GRB 171123A (Evans et al. GCN Circ. 22148). In these
data, the afterglow is clearly detected, and the light curve shows an
initial decay and plateau, typical of GRB afterglows. The best position
currently available was given by Goad et al. (GCN Circ. 22150). This
position is ~15 arcsec from that reported in GCN 22148. This is because 
the object lay ~14 arcsec outside the field of view of the 
promptly-available XRT data, so only the edges of the PSF were available for
source localisation.

As ever, the automated XRT analysis can be viewed at
http://www.swift.ac.uk/xrt_products/00791922.

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


GRB_name: GRB171123A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22152
SUBJECT: GRB 171123A: Swift-XRT refined Analysis
DATE:    17/11/23 22:04:20 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), J.A. Kennea (PSU), B.
Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), S.L. Gibson (U.
Leicester), J.P. Osborne (U. Leicester), V. D'Elia (ASDC) and P.A.
Evans report on behalf of the Swift-XRT team:

We have analysed 6.5 ks of XRT data for GRB 171123A (Evans et al. GCN
Circ. 22148), from 98 s to 19.7 ks after the  BAT trigger. The data are
entirely in Photon Counting (PC) mode. The enhanced XRT position for
this burst was given by Goad et al. (GCN Circ. 22150).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=3.4 (+0.7, -0.6). At T+306 s  the decay
flattens to an alpha of -0.33 (+0.25, -0.45) before breaking again at
T+1892 s to a final decay with index alpha=0.68 (+0.13, -0.14).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.21 (+0.22, -0.21). The
best-fitting absorption column is  8.8 (+5.1, -4.4) x 10^20 cm^-2, in
excess of the Galactic value of 1.9 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 2.9 x 10^-11 (3.8 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      8.8 (+5.1, -4.4) x 10^20 cm^-2
Galactic foreground: 1.9 x 10^20 cm^-2
Excess significance: 2.6 sigma
Photon index:      2.21 (+0.22, -0.21)

If the light curve continues to decay with a power-law decay index of
0.68, the count rate at T+24 hours will be 0.010 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.0 x
10^-13 (3.8 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00791922.

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


GRB_name: GRB171123A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22153
SUBJECT: GRB 171123A: Swift-BAT refined analysis
DATE:    17/11/24 00:14:52 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), P. A. Evans (U Leicester),
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
(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 171123A (trigger #791922)
(Evans et al., GCN Circ. 22148).  The BAT ground-calculated position is
RA, Dec = 186.198, 32.503 deg which is
  RA(J2000)  =  12h 24m 47.6s
  Dec(J2000) = +32d 30' 12.5"
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 86%.

The mask-weighted light curve shows a weak pulse that starts at ~T-1 s and ends
at ~T+20 s, with a tail lasting till ~T+60 s. In addition, there is a weak
precursor from ~T-25 s to ~T-20 s. T90 (15-350 keV) is 58.5 +- 27.1 sec
(estimated error including systematics).

The time-averaged spectrum from T-1.39 to T+60.29 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.35 +- 0.34.  The fluence in the 15-150 keV band is 4.8 +- 1.0 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-0.27 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/791922/BA/


GRB_name: GRB171123A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22154
SUBJECT: GRB 171123A: MITSuME Akeno optical upper limits
DATE:    17/11/24 07:02:25 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata@u.phys.nagoya-u.ac.jp>

K. Morita, R. Itoh, K. L. Murata, T. Yoshii, Y. Tachibana, S. Harita, T.
Ozawa, H. Mamiya, K. Shiraishi, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 171123A (P. A. Evans  et
al., GCN Circular #22148) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of Akeno Observatory,
Yamanashi, Japan.
The observation started on 2017-11-23 16:24:30.61 UT. We did not find any
new point source within enhanced XRT circle (M.R. Goad et al., GCN Circular
#22150) in all three bands.
We obtained following limits for the magnitudes.

T0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic
-------------------------------------------------------------------------------------------------------
~3.15       18:56:14.59      9360     >21.1    >20.7     >19.6
-------------------------------------------------------------------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.


GRB_name: GRB171124A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22155
SUBJECT: GRB 171124A: Swift ToO observations
DATE:    17/11/24 11:51:18 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Swift has initiated a ToO observation of the Fermi/LAT GRB 171124A. 
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020784

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Fermi/LAT event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a 
GCN Circular after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

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


GRB_name: GRB171124A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22156
SUBJECT: GRB 171124A: Fermi-LAT detection
DATE:    17/11/24 11:56:09 GMT
FROM:    Elisabetta Bissaldi at U.Innsbruk/IAPP  <Elisabetta.Bissaldi@uibk.ac.at>

F. Longo (University and INFN, Trieste), M. Arimoto (Waseda University),
E. Bissaldi (Politecnico and INFN Bari) and M. Palatiello (University 
and INFN, Trieste)
report on behalf of the Fermi-LAT collaboration:


At 05:37:56.50 UT on November 24, 2017, Fermi-LAT
detected high-energy emission from GRB 171124A, which was also
detected by Fermi-GBM (trigger 533194681 / 171124235).

The best LAT on-ground location is found to be

RA, Dec = 335.52, 35.22 deg (J2000)

with an error radius of 0.18 deg (90 % containment, statistical error 
only).

This was 19 deg from the LAT boresight at the time of the trigger.
More than 10 photons with Energy > 100 MeV are associated to
the GRB in 350 s. The highest-energy photon is a 3.5 GeV event,
which is observed 4 seconds after the GBM trigger.

A Swift ToO has been approved for this burst.

The Fermi-LAT point of contact for this burst
is Francesco Longo (francesco.longo@ts.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.


GRB_name: GRB171123A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22157
SUBJECT: GRB 171123A: GMG observation limit
DATE:    17/11/24 12:55:39 GMT
FROM:    Jirong Mao at Yunnan Obs  <jirongmao_obs@ynao.ac.cn>

J. Mao, C.-J. Wang and J.-M. Bai (YNAO) report:


We observed the field of GRB 171123A (Evans et al., GCN 22148) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatories. Observations began from 21:02:44 UT, about 6.8 hours after the trigger. We did not detect any source within the X-ray afterglow position error circle (Goad et al. GCN 22150), down to a limit of R~21.6 mag.


GRB_name: GRB171123A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22158
SUBJECT: GRB 171123A: Swift/UVOT Upper Limits
DATE:    17/11/24 13:06:31 GMT
FROM:    Sam Emery at MSSL-UCL  <samuel.emery.15@ucl.ac.uk>

S.W.K. Emery (UCL-MSSL) and P. A. Evans (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 171123A
94 s after the BAT trigger (Evans et al., GCN Circ. 22148).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 22150)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            94          243          147         >20.9
u_FC               308          557          246         >20.5
white               94         2397          489         >21.0
v                  637         2447          214         >18.8
b                  563         2373          194         >19.7
uvw1             13669        18855         1209         >20.7
uvm2             12763        13663          886         >20.6
uvw2             23870        35081         1032         >21.1


The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB171124A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22159
SUBJECT: GRB 171124A: MITSuME Akeno optical upper limits
DATE:    17/11/24 14:58:20 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata@u.phys.nagoya-u.ac.jp>

K. Shiraishi, R. Itoh, K. L. Murata, T. Yoshii, Y. Tachibana, S. Harita, K.
Morita, T.
Ozawa, H. Mamiya, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 171124A (F. Longo  et
al., GCN Circular #22156) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of Akeno Observatory,
Yamanashi, Japan.
The observation started on 2017-11-24 11:02:40.53 UT. We did not find any
new point source within enhanced LAT circle in all three bands.
We obtained following limits for the magnitudes.

T0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic
------------------------------------------------------------
-------------------------------------------
~6.38       12:00:00      300     >19.0     >18.5         >17.4
------------------------------------------------------------
-------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used UCAC-4 catalog for flux calibration.


GRB_name: GRB171123A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22160
SUBJECT: GRB 171123A: RATIR Optical and NIR Observations
DATE:    17/11/24 15:06:18 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), JesÃºs
GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey Moseley (GSFC), John
Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:

We observed the field of GRB 171123A (Evans, et al., GCN 22148) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on
Sierra San Pedro MÃ¡rtir from 2017/11 24.47 to 2017/11 24.54 UTC (21.06 to
22.77 hours after the BAT trigger), obtaining a total of 1.07 hours
exposure in the r and i bands and 0.45 hours exposure in the Z, Y, J, and H
bands.

For a source within the Swift-XRT error circle (Goad, et al., GCN 22150),
in comparison with the SDSS DR9 and 2MASS catalogs, we obtain the following
upper limits (3-sigma):

 r > 23.60
 i > 23.39
 Z > 22.23
 Y > 21.69
 J > 21.43
 H > 21.02

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB171123A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22161
SUBJECT: GRB 171123A: Nanshan-1m optical upper limit
DATE:    17/11/24 15:38:53 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

Z.P. Zhu, H.X. Feng, D. Xu (NAOC), Z. Fan, W. Wang, J. Zheng, N. Song 
(NAOC), S.G. Ma, J. Liu (XAO), Y.D. Hu (IAA-CSIC) report

We observed the field of GRB 171123A (Evans et al., GCN 22148) using the 
1-m telescope located at Nanshan, Xinjiang, China. We obtained 3x120s, 
1x180s SDSS i-band and 1x120s r-band frames, starting at 21:12:40 UT on 
2017-11-23, i.e., 6.8 hr after the BAT trigger.

No optical source was detected in the stacked image at the XRT position 
(Goad et al., GCN 22150), down to a limiting magnitude of i~20.6 mag, at 
the median time of 6.92 hr post-burst, calibrated with the SDSS field.


GRB_name: GRB171123A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22162
SUBJECT: GRB 171123A: Tautenburg observations
DATE:    17/11/24 16:01:55 GMT
FROM:    Sylvio Klose at TLS Tautenburg  <klose@tls-tautenburg.de>

S. Schmidl, B. Stecklum, S. Klose, A. Nicuesa Guelbenzu, and C. Hoegner 
(Thueringer Landessternwarte Tautenburg) report:


We observed the field of GRB 171123A (Evans et al., GCN 22148) in the Rc 
band using the Tautenburg Schmidt telescope equipped with the prime focus 
CCD camera. Observations started at 04:01 UT, about 14 hr after the burst.

At the SE border of the enhanced XRT error circle (radius 1.9 arcsec; Goad 
et al., GCN 22150; 1.5 arcsec acc. to the newest results presented at
http://www.swift.ac.uk/xrt_positions/00791922/) we find a faint source at 
coordinates

RA (J2000) : 12:24:59.29,
Dec (J2000): 32:30:03.4  (+/- 0.6 arcsec).

At a midtime of 04:46 UT we measure a preliminary magnitude of Rc (Vega) = 
22.7 +/- 0.3, calibrated against SDSS field stars.

The non-detection of this source by RATIR eight hours after our observing 
run (Butler et al., GCN 22160) suggests that this was the GRB afterglow. 
We caution however that this is only a 3-sigma detection.


GRB_name: GRB171119A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22163
SUBJECT: GRB 171119A: AstroSat CZTI detection
DATE:    17/11/24 16:11:56 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:
 
Analysis of Astrosat CZTI data showed the detection of GRB 171119A, which was also detected by IPN Triangulation (Hurley K. et al., GCN 22146) and Konus-Wind observation (Frederiks D. et al., GCN 22147).
 
The source was clearly detected in the 40-200 keV energy range. The light curve of the CZT detector shows a multiple peak of emission at 23:48:33 UT. The measured peak count rate is 611.9 cts/s above the background in combined data of four quadrants, with a total of 2704 cts. The local mean background count rate was 263.1 cts/s. Using cumulative rates, we measure a T90 of 10.3 s.
 
It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The Veto light curve shows a strong peak coincident with the peak in the CZT detector.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB171124A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22164
SUBJECT: GRB 171124A: Fermi GBM observation
DATE:    17/11/24 16:35:48 GMT
FROM:    Elisabetta Bissaldi at U.Innsbruk/IAPP  <Elisabetta.Bissaldi@uibk.ac.at>

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


"At 05:37:56.50 UT on 24 November 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171124A (trigger 533194681 / 171124235),
which was also detected by Fermi LAT (Longo et al. 2017, GCN 22156).
The GBM on-ground location is consistent with the LAT position.

The angle from the Fermi LAT boresight at the GBM trigger time is 19 degrees.

The GBM light curve consists of two emission episodes
with a duration (T90) of about 26 s (50-300 keV).
The time-averaged spectrum from T0-1.3 s to T0+22 s is
well fit by a Band function with Epeak = 1.12 +/- 0.28 MeV,
alpha = -1.01 +/- 0.05, and beta = -2.10 +/- 0.22.

The event fluence (10-1000 keV) in this time interval is
(1.1 +/- 0.3)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+7.3 s in the 10-1000 keV band
is 4.5 +/- 0.2 ph/s/cm^2.


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


GRB_name: GRB171124A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22165
SUBJECT: GRB 171124A: Swift-XRT observations
DATE:    17/11/24 17:36:28 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.P. Osborne (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri
(INAF-OAB), P. D'Avanzo (INAF-OAB), D.N. Burrows (PSU), A. Tohuvavohu
(PSU), S. J. LaPorte (PSU), K.L. Page (U. Leicester), A.P. Beardmore
(U. Leicester) and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:

Swift-XRT has performed follow-up observations of the
Fermi/LAT-detected burst GRB 171124A (Longo et al. GCN Circ. 22156),
collecting 4.6 ks of Photon Counting (PC) mode data between T0+21.8 ks
and T0+33.1 ks. 

Four uncatalogued X-ray sources have been detected, however none of
them is above the RASS limit or shows definitive signs of fading.
Therefore, at the present time we cannot identify which, if any, is the
afterglow. Details of these sources are given below:

Source 1:
  RA (J2000):  335.42198  =  22:21:41.28
  Dec (J2000): +35.14890  =  +35:08:56.0
  Error: 2.8 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: (7.5 +/- 1.5)e-3 ct s^-1  
  Distance: 385 arcsec from Fermi/LAT position.
  Flux: (1.85 +/- 0.38)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 2:
  RA (J2000):  335.47618  =  22:21:54.28
  Dec (J2000): +35.33200  =  +35:19:55.2
  Error: 2.3 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: 0.0243 +/- 0.0029 ct s^-1   
  Distance: 423 arcsec from Fermi/LAT position.
  Flux: (7.33 +/- 0.86)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 3:
  RA (J2000):  335.3767  =  22:21:30.42
  Dec (J2000): +35.1638  =  +35:09:49.7
  Error: 4.6 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: (3.52 [+1.20, -0.99])e-3 ct s^-1  
  Distance: 467 arcsec from Fermi/LAT position.
  Flux: (1.10 [+0.38, -0.31])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 4:
  RA (J2000):  335.49592  =  22:21:59.02
  Dec (J2000): +35.16340  =  +35:09:48.2
  Error: 2.8 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: (5.6 +/- 1.3)e-3 ct s^-1  
  Distance: 215 arcsec from Fermi/LAT position.
  Flux: (2.04 +/- 0.49)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
http://www.swift.ac.uk/ToO_GRBs/00020784.

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


GRB_name: GRB171123A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22166
SUBJECT: GRB 171123A: OSN Upper Limit
DATE:    17/11/24 18:52:37 GMT
FROM:    Luca Izzo at IAA-CSIC  <Luca.Izzo@ICRA.it>

L. Izzo, D. A. Kann, A. de Ugarte Postigo (all HETH/IAA-CSIC), and V. Casanova (IAA-CSIC)  report:

We observed the field of GRB 171123A  (Evans et al.; GCN Circ. 22148) with the 1.5-m OSN telescope in Granada, Spain.

We began observing at 03:32:53 UT (13.3 hours after the GRB trigger), and obtained 18x300s images in the Ic band. Observations were obtained in inclement conditions (clouds, bad seeing of ~2")  and the last four images could not be used.

In our stacked image, we find no source at the position reported by Schmidl et al. (GCN Circ. 22162) down to a a 3-sigma limit of Ic (Vega) > 21.  The calibration was performed using nearby stars in the USNO B1 catalog.


GRB_name: GRB171124A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22168
SUBJECT: GRB 171124A: AstroSat CZTI detection
DATE:    17/11/24 21:17:53 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:

Analysis of Astrosat CZTI data showed the detection of a GRB 171124A, which was also detected by Fermi-LAT (Longo F. et al., GCN 22156) and Fermi-GBM (Bissaldi E. et al., GCN 22164).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 05:38:00.500 UT, ~4 s after the Fermi trigger. The measured peak count rate is 161.3 cts/s above the background in combined data of four quadrants, with a total of 1157 cts. The local mean background count rate was 424.7 cts/s. Using cumulative rates, we measure a T90 of 8.4 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB171123A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22169
SUBJECT: GRB 171123A: TShAO optical upper limit
DATE:    17/11/24 23:05:11 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI), A. Kusakin (Fesenkov Astrophysical Institute),   I. 
Reva (Fesenkov Astrophysical Institute),   E. Mazaeva (IKI), A. 
Pozanenko (IKI)   report on behalf of larger GRB follow-up collaboration:

We observed the field of the Swift  GRB 171123A   (Evans et al.,
GCN  22148) with Zeiss-1000 1-m telescope of Tien Shan Astronomical 
Observatory starting on Nov., 23 (UT) 23:31:56.  We took several images 
in R-filter.  Within enhanced XRT error circle  (Goad et al., GCN 22150) 
we do not detect  any  object.  Preliminary  photometry of the afterglow 
is following

Date       UT start  t-T0    Filter Exp.   OT     Err. UL
                      (mid, days)     (s)             (3 sigma)

2017-11-23 23:31:56  0.41294  R    38*120  n/d    n/d  22.2

Photometry is based on nearby USNO-B1.0 stars, R2 magnitude.


GRB_name: GRB171126A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22170
SUBJECT: GRB 171126A: Fermi GBM detection
DATE:    17/11/26 18:18:29 GMT
FROM:    C. Michelle Hui at MSFC/Fermi-GBM  <c.m.hui@nasa.gov>

C. M. Hui (NASA/MSFC) and C. Meegan (UAH)
reports on behalf of the Fermi GBM Team:

At 05:38:43.71 UT on 26 November 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171126A (trigger 533367528/171126235).

The on-ground calculated location, using the GBM trigger data,
is RA = 237.84, DEC = +46.76 (J2000 degrees,
equivalent to 15h 51m, +46d 42'), with an uncertainty of 3.29 degrees
(radius, 1-sigma containment, statistical only; there is additionally
a systematic error which we have characterized as a
core-plus-tail model, with 90% of GRBs having a 3.7 deg error
and a small tail suffering a larger than 10 deg systematic error
[Connaughton et al. 2015, ApJS, 216, 32] ).

The trigger resulted in an Autonomous Repoint Request (ARR)
by the GBM Flight Software owing to the high peak flux of the GRB.
This ARR was accepted and the spacecraft slewed to the GBM in-flight
location.  The angle from the Fermi LAT boresight is 50 degrees.

The GBM light curve shows a single bright peak followed by
a secondary emission with a duration (T90) of about 1.47s (50-300 keV).
The time-averaged spectrum from T0+0.0s to T0+2.08s is
adequately fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.66 +/- 0.05 and
the cutoff energy, parameterized as Epeak, is 89.36 +/- 2.52 keV.

The event fluence (10-1000 keV) in this time interval is
(2.074 +/- 0.042)E-06 erg/cm^2. The 64ms peak photon flux measured
starting from T0+0.192s in the 10-1000 keV band is 97.21 +/- 6.07 ph/s/cm^2.

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


GRB_name: GRB171124A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22171
SUBJECT: GRB 171124A: Insight-HXMT/HE detection
DATE:    17/11/27 14:06:03 GMT
FROM:    Li Xufang at IHEP  <lixufang@ihep.ac.cn>

X.F. Li, S. L. Xiong, X. B. Li, C. K. Li, C. Z. Liu,
Z. W. Li, Z. Chang, X. F. Lu, J. L. Zhao, A. M. Zhang, Y. F. Zhang,
C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU),
F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:

During the commissioning phase, at 2017-11-24T05:38:03.000 (T0),
Insight-HXMT/HE detected GRB 171124A (trigger ID: HEB171124234)
in a routine search of the data, which was also observed by
Fermi-LAT (F. Longo et al, GCN Circ.22156), Fermi/GBM(E. Bissaldi 
et al, GCN Circ.22164)ï¼ŒAstroSat CZTIï¼ˆV. Sharma et alï¼ŒGCN Circ.22168ï¼‰.


The Insight-HXMT light curve mainly consists of two emission episodes
with a duration (T90) of 17.27 s measured from T0-5.66 s.
The 1-s peak rate, measured from T0-0.007 s, is 924.7 cnts/sec.
The total counts from this burst is 3968.2 counts.

URL_LC: http://www.hxmt.org/images/GRB/HEB171124234_lc.jpg

All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.

The analysis results presented above are preliminary;
final results will be published elsewhere.

Insight-HXMT is the first Chinese space X-ray telescope, which was funded
jointly by the China National Space Administration (CNSA) and the Chinese
Academy of Sciences (CAS). More information about it could be found at:
http://www.hxmt.org/index.php/enhome .


GRB_name: GRB171124A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22174
SUBJECT: GRB 171124A: Swift-XRT afterglow detection
DATE:    17/12/01 11:21:08 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.P. Osborne (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri
(INAF-OAB), P. D'Avanzo (INAF-OAB), D.N. Burrows (PSU), A. Tohuvavohu
(PSU), S. J. LaPorte (PSU), K.L. Page (U. Leicester), A.P. Beardmore
(U. Leicester) and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:

Swift-XRT has conducted further observations of the field of the
Fermi/LAT-detected burst GRB 171124A (Longo et al. GCN Circ. 22156).
The observations now extend from T0+21.8 ks to T0+579.1 ks. 

Of the sources reported by Osborne et al. (GCN Circ. 22165), "Source 2"
is fading with 3-sigma significance, and is therefore likely the GRB
afterglow. Using 4982 s of PC mode data and 3 UVOT images, we find an
enhanced XRT position (using the XRT-UVOT alignment and matching UVOT
field sources to the USNO-B1 catalogue): RA, Dec = 335.47598, +35.33213
which is equivalent to:

RA (J2000): 22h 21m 54.24s
Dec(J2000): +35d 19' 55.7"

with an uncertainty of 2.3 arcsec (radius, 90% confidence). This
position is 7.1 arcmin from the Fermi/LAT position.  The source is
fading with alpha >0.7.

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.8 (+0.8, -0.7). The
best-fitting absorption column is  7.9 (+4.7, -3.5) x 10^21 cm^-2, in
excess of the Galactic value of 1.3 x 10^21 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 2.9 x 10^-11 (1.0 x 10^-10) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      7.9 (+4.7, -3.5) x 10^21 cm^-2
Galactic foreground: 1.3 x 10^21 cm^-2
Excess significance: 3.1 sigma
Photon index:      2.8 (+0.8, -0.7)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020784.
The results of the full analysis of the XRT observations are available
at http://www.swift.ac.uk/ToO_GRBs/00020784.

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


GRB_name: GRB171124A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22175
SUBJECT: GRB 171124A: TShAO optical observations
DATE:    17/12/01 12:48:25 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), A. Pozanenko (IKI), A. Kusakin (FAPHI),  I. Reva 
(FAPHI), A. Volnova (IKI) report on behalf of  larger GRB follow-up 
collaboration:

We observed the field  of the Fermi/LAT-detected burst GRB 171124A 
(Longo et al. GCN   22156) with Zeiss-1000 1-m telescope of Tien Shan 
Astronomical Observatory starting on Nov. 27 (UT) 12:28:32. We took 
several images in R-filter with exposures of 120 s. We cover all LAT- 
localization region.
The three XRT sources ## 1,3,4 (Osborne  et al. GCN   22165)  are 
detected in our stacked image. These sources are also presented in the 
USNO-B1.0 catalogue. We do not detect any optical object within X-ray 
afterglow (XRT #2 error circle, Osborne  et al. GCN  22174).  We may 
note that 4.5 arcsec South of XRT #2    we detect a galaxy which is also 
present in USNO-B1.0.

Preliminary photometry of the field is following:

Date       UT start   t-T0    Filter Exp.   OT   Err. UL
                      (mid, days)     (s)              (3 sigma)

2017-11-27 12:28:32  3.31825  R    40*120  n/d  n/d  22.0

The  finding chart of the 32 XRT source  can be found at
http://grb.rssi.ru/GRB171124A/GRB171124A_XRT2.png

The photometry is based on nearby USNO-B1.0 stars

USNO-B.1_id R2
1251-0500105 14.64
1252-0499091 16.06
1251-0500220 15.86
1251-0500271 16.17
1251-0500270 16.12
1251-0500372 16.06


GRB_name: GRB171126A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22176
SUBJECT: GRB 171126A: AstroSat CZTI detection
DATE:    17/12/02 19:48:44 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma (IUCAA), V. Bhalerao (IIT-B), D. Bhattacharya (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:

Analysis of Astrosat CZTI data showed the detection of a GRB 171126A, which was also detected by Fermi-GBM (Hui C.M. et al., GCN 22170).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 05:38:43.810 UT. The measured peak count rate is 530.2 cts/s above the background in combined data of four quadrants, with a total of 2675 cts. The local mean background count rate was  399.8 cts/s. Using cumulative rates, we measure a T90 of 1.1 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB171205A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22177
SUBJECT: GRB 171205A: Swift detection of a burst
DATE:    17/12/05 07:48:19 GMT
FROM:    Boris Sbarufatti at PSU  <bxs60@psu.edu>

V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Y. Lien (GSFC/UMBC) and
B. Sbarufatti (PSU) report on behalf of the Swift Team:

At 07:20:43 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 171205A (trigger=794972).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 167.447, -12.604 which is 
   RA(J2000) = 11h 09m 47s
   Dec(J2000) = -12d 36' 12"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty). As is usual with an image trigger, the available
BAT light curve shows no significant structure. 

The XRT began observing the field at 07:23:08.5 UT, 144.7 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 167.4144, -12.5857 which is equivalent to:
   RA(J2000)  = +11h 09m 39.46s
   Dec(J2000) = -12d 35' 08.5"
with an uncertainty of 5.0 arcseconds (radius, 90% containment). This
location is 132 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 153 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
0.05. 

Burst Advocate for this burst is V. D'Elia (delia 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: GRB171205A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22178
SUBJECT: GRB 171205A: Likely association with low-z spiral galaxy
DATE:    17/12/05 08:38:42 GMT
FROM:    Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>

L. Izzo, D. A. Kann (both HETH/IAA-CSIC), J. P. U. Fynbo (DARK), A. J.
Levan (U. Warwick), and N. R. Tanvir (U. Leicester) note on behalf of the
Stargate Consortium:

The XRT position of GRB 171205A (V. D'Elia et al. GCN #22177) contains a
bright spiral galaxy 2MASX J11093966-1235116 which lies at z = 0.037
according to SIMBAD (6df Galaxy Catalog).

The combination of a BAT image trigger, a bright XRT afterglow and lack of
a bright optical afterglow may indicate a source similar to XRFs 060218
and 100316D.

Multiwavelength follow-up is encouraged.


GRB_name: GRB171205A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22179
SUBJECT: GRB 171205A: Enhanced Swift-XRT position
DATE:    17/12/05 10:32:58 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 1358 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 171205A, 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 = 167.41406, -12.58891 which is equivalent
to:

RA (J2000): 11h 09m 39.37s
Dec (J2000): -12d 35' 20.1"

with an uncertainty of 2.3 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) and Evans
et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22180
SUBJECT: GRB 171205A: VLT/X-shooter optical counterpart and spectroscopic observations
DATE:    17/12/05 11:01:51 GMT
FROM:    Jonatan Selsing at DARK/NBI  <jselsing@dark-cosmology.dk>

L. Izzo (HETH/IAA-CSIC), J. Selsing (DARK), J. Japelj (API, Univ. Amsterdam), B.
Milvang-Jensen, J. P. U. Fynbo (both DARK), D. Xu (NAOC), D. A. Kann
(HETH/IAA-CSIC), N. R. Tanvir, R. Starling (both U. Leicester), A. J. Levan, K.
Wiersema (both U. Warwick), G. Pugliese (API, Univ. Amsterdam), V. D'Elia
(ASI-SSDC), and S. Campana (INAF-Brera) report on behalf of the Stargate
Consortium:

We observed the optical afterglow of GRB 171205A (V. D'Elia et al. GCN #22177)
with the ESO VLT/X-shooter spectrograph, covering the wavelength range
3500-20000 AA. Spectroscopy started at 08:56:18 UT on 2017-12-05 (i.e., 1.5 hr
after the GRB) and consisted of 1 exposure of 600 s taken in twilight.

From the acquisition image prior to the spectroscopy, a new optical transient is
clearly detected in the outskirts of the putative host galaxy (L. Izzo et al.
GCN #22178) at the following coordinates:

RA(J2000) = 11h 09m 39.573s Dec.(J2000) = -12d 35' 17.37"

This source is inside the error box reported by (J.P. Osborne et al. GCN
#22179). From the acquisition image we measure this source to have m(r)~16.0
mag, calibrated with a nearby Pan-STARRS star.

The source continuum is well detected across the entire spectral coverage and
clear emission lines are superposed on it identified as Halpha, [N II] 6584, and
[S II] 6717/32 located at z = 0.0368, suggesting an association with the nearby
galaxy. Additionally, a tentative detection of absorption lines identified as
NaI 5891/5897 in the continuum further supports z = 0.0368 as the redshift of
the GRB.

We acknowledge the excellent support from the ESO staff, particularly Jose
Velasquez and Zahed Wahhaj in obtaining these observations.


GRB_name: GRB171205A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22181
SUBJECT: GRB 171205A: Swift/UVOT Detection
DATE:    17/12/05 13:45:32 GMT
FROM:    Sam Emery at MSSL-UCL  <samuel.emery.15@ucl.ac.uk>

S.W.K. Emery (UCL-MSSL) and V. D'Elia (ASDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 171205A
154 s after the BAT trigger (D'Elia et al., GCN Circ. 22177).
A source consistent with the XRT position
(J.P. Osborne et al. GCN Circ. 22179)
is detected in the initial UVOT exposures.
There is marginal evidence for brightening in the white filter.
The revised source position is
RA(J2000)=11:09:39.547 Dec.(J2000)=-12:35:17.93. This position
 is within the XRT error circle  and is consistent with the VLT/X-shooter
 optical position  (L. Izzo et al. GCN Circ. 22180).

Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white_FC           154          303          147         18.10 +/- 0.08
white             3812         3849           36         17.70 +/- 0.09
u                  312          390           78         17.78 +/- 0.18
v                 4499         4698          197         18.22 +/- 0.15
b                 3607         3807          197         18.45 +/- 0.09
uvw1              4908         5108          197         17.13 +/- 0.09
uvm2              4703         4903          197         17.11 +/- 0.11
uvw2              4294         4494          197         16.96 +/- 0.10

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 in the direction of the burst
(Schlegel et al. 1998), nor from any contribution of the host galaxy.


GRB_name: GRB171205A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22182
SUBJECT: GRB 171205A: RATIR Optical and NIR Observations
DATE:    17/12/05 15:10:17 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), JesÃºs
GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey Moseley (GSFC), John
Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:

We observed the field of GRB 171205A (D'Elia, et al., GCN 22177) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on
Sierra San Pedro MÃ¡rtir from 2017/12 5.40 to 2017/12 5.53 UTC (2.15 to 5.36
hours after the BAT trigger), obtaining a total of 1.44 hours exposure in
the r and i bands and 0.71 hours exposure in the Z and Y bands.

In comparison with the USNO-B1 and 2MASS catalogs, we detect and obtain the
following photometry for the source reported by Izzo et al. (GCN 22180):

 r = 18.30 +/- 0.05
 i = 18.13 +/- 0.02
 Z = 18.35 +/- 0.05
 Y = 18.13 +/- 0.05

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB171205A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22183
SUBJECT: GRB 171205A: Swift-XRT refined Analysis
DATE:    17/12/05 16:08:33 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU),
P.A. Evans (U. Leicester), S.L. Gibson (U. Leicester), J.P. Osborne (U.
Leicester), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB) and V.
D'Elia report on behalf of the Swift-XRT team:

We have analysed 6.6 ks of XRT data for GRB 171205A (D'Elia et al. GCN
Circ. 22177), from 134 s to 22.5 ks after the  BAT trigger. The data
comprise 238 s in Windowed Timing (WT) mode (the first 9 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Osborne et
al. (GCN Circ. 22179).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=1.84 (+0.10, -0.18). At T+289 s  the decay
steepens to an alpha of 2.43 (+0.09, -0.08) before breaking again at
T+5714 s to a final decay with index alpha=-0.16 (+0.28, -0.69).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.717 (+0.035, -0.024). The
best-fitting absorption column is  consistent with the Galactic value
of 5.9 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum  is 3.7 x 10^-11 (4.1 x 10^-11) erg cm^-2 count^-1. 

A summary of the WT-mode spectrum is thus:
Galactic foreground: 5.9 x 10^20 cm^-2
Intrinsic column:    5.89 (+/-0.22) x 10^20 cm^-2 at z=0.0368
Photon index:      1.717 (+0.035, -0.024)

If the light curve continues to decay with a power-law decay index of
-0.16, the count rate at T+24 hours will be 0.025 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.1 x
10^-13 (1.0 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00794972.

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


GRB_name: GRB171205A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22184
SUBJECT: GRB 171205A: Swift-BAT refined analysis
DATE:    17/12/05 17:49:14 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
V. D'Elia (ASDC), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(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 171205A (trigger #794972)
(D'Elia et al., GCN Circ. 22177).  The BAT ground-calculated position is
RA, Dec = 167.423, -12.599 deg which is
 RA(J2000)  =  11h 09m 41.5s
 Dec(J2000) = -12d 35' 58.0"
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 46%.

The mask-weighted light curve shows some weak emissions with multiple
overlapping peaks that starts at ~ T-40 s and ends at ~ T+200 s. The burst
went out of the BAT FOV at T+478 s. T90 (15-350 keV) is 189.4 +- 35.0 sec
(estimated error including systematics).

The time-averaged spectrum from T-42.23 to T+197.80 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.41 +- 0.14.  The fluence in the 15-150 keV band is 3.6 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+49.08 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.

Assuming z = 0.0368 (Izzo et al., GCN Circ. 22180) and a standard cosmology model
with H_0 = 70.5 km/s/Mpc, Omega_M = 0.274, Omega_\Lambda = 0.726 (Spergel et al. 2007),
the isotropic energy release Eiso (in the observed 15-150 keV band) is 5.72e+49 erg.
This Eiso is similar to other low-luminosity GRBs. For example, the Eiso
(in the observed 15-150 keV band) for GRB060218 is 2.57e+49 erg (assuming
T90 = 2100 s based on Campana et al. 2006) and GRB100316D has Eiso >= 3.70e+49 erg
(assuming T90 >= 1300 s based on Starling et al. 2011).

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/794972/BA/


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22186
SUBJECT: GRB 171205A: GMG observation
DATE:    17/12/06 03:54:39 GMT
FROM:    Jirong Mao at Yunnan Obs  <jirongmao_obs@ynao.ac.cn>

J. Mao, X. Ding and J.-M. Bai (YNAO) report:


We observed the field of GRB 171205A (D'Elia et al., GCN 22177) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatories. Observations began from 22:45:21 UT, about 15.4 hours after the trigger. We clearlydetected the optical counterpart reported by Izzo et al. (GCN 22180). A very preliminary result was estimated as R~20.4 mag. We note that this source is in the outskirts of the host galaxy and the magnitude that we roughly measured has large uncertainty. Detailed analysis is ongoing.


GRB_name: GRB171205A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22187
SUBJECT: GRB 171205A: NOEMA detection of a bright mm afterglow
DATE:    17/12/06 10:26:44 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), 
S. Schulze (Weizmann), M. Bremer, M. Krips (IRAM), 
C.C. Thoene, L. Izzo, D.A. Kann, Z. Cano, K. Bensch 
(HETH/IAA-CSIC), S. Martin Ruiz, I. de Gregorio (ALMA), 
S. Kim (PUC), R. SÃ¡nchez-Ramirez (INAF-IAPS), 
D. Malesani (DARK/NBI) report:

We observed the afterglow of GRB 171205A with 
NOEMA at 150GHz and 90GHz starting at 3:30 UT on the 
6th of December (20.2 hrs after the GRB onset). We 
detect a bright afterglow in 150GHz with a preliminary 
flux density estimate of 35-40 mJy. The coordinates 
of the detected source are (J2000 +/- 0.05"):

R.A.: 11:09:39.52
Dec.: -12:35:18.34

We note that if the flux density is confirmed, it would be 
the second brightest GRB ever detected in mm/submm 
wavelengths, after GRB 030329 (for a review on 
mm/submm data of GRBs see de Ugarte Postigo et al. 
2012).

Further follow-up observations are encouraged.


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22188
SUBJECT: GRB 171205A: LSGT optical afterglow follow-up observation
DATE:    17/12/06 13:17:04 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

Changsu Choi, Myungshin Im (CEOU/SNU), on behalf of a larger collaboration


We observed the field of GRB 171205A (D'Elia et al., GCN 22177) with
SNUCAM-II (Choi & Im 2017, JKAS, 50, 71) on the 0.43m Lee Sang Gak
Telescope (LSGT; Im et al. 2015, JKAS, 48. 207) at the Siding Spring
Observatory in Australia. The observation started at about 9 hours after
the BAT alert, using r, i, z (broad-band), m425, m475, m525, m575, and m625
(medium-band) filters.


We clearly identify the optical afterglow in these bands, and preliminary
photometry results in r, i, and z filters are reported below. Note that the
photometric calibration is based on stars from the Pan-Starrs catalog in
the vicinity of GRB 171205A, and systematic errors due to host galaxy
subtraction uncertainty could amount to a few tenths of magnitude.


Filter Mag err UT(center)

r18.0 0.1 2017-12-05T16:17:17

i 18.1 0.1 2017-12-05T16:26:55

z 18.3 0.2 2017-12-05T16:36:33


Further observations and analysis are being carried out.


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22189
SUBJECT: GRB 171205A: TNG NIR detections
DATE:    17/12/06 15:45:49 GMT
FROM:    Andrea Melandri at INAF-OAB  <andrea.melandri@brera.inaf.it>

A. Melandri, P. D'Avanzo (INAF-OAB), L. di Fabrizio, C. Padilla (INAF-TNG), V. D'Elia (ASI/ASDC) report on behalf of the CIBO collaboration:


We observed the field of GRB 171205AA (D'Elia et al. GCN 22177) with the 3.6m Telescopio Nazionale Galileo (TNG) equipped with NICS. Observations were carried out in the near-infrared with the JHK filter, starting on Dec 06 at 05:25:09 UT (~0.92 days after the burst) and consisted in a series of images for a total exposure time of 15 minutes per filter.

We clearly detect the optical counterpart (Izzo et al. GCN 22180; Emery & D'Elia GCN 22181; Butler et al. GCN 22182; Mao et al. 22186; de Ugarte Postigo et al. GCN 22187; Choi et al. GCN 22188) in each filter. In our preliminary analysis the source is detected with a magnitude of J = 16.7 +/- 0.1 at a mid time of 0.922 days from the burst event (calibrated against nearby stars reported in the 2MASS catalogue).

Further observations are planned.


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22190
SUBJECT: GRB 171205A: GOTO detection of the optical counterpart
DATE:    17/12/06 16:56:54 GMT
FROM:    Rhaana Starling at U of Leicester  <rlcs1@leicester.ac.uk>

D.Steeghs, R.Cutter, K.Ulaczyk, D.Pollacco, R.West, A.Levan, J.Lyman, P.Chote, J.McCormac, K.Wiersema (U. Warwick)
G.Ramsay (Armagh O.)
R.Starling, P.O'Brien, R.Eyles (U. Leicester)
D.K.Galloway, E.Rol, E.Thrane, K.Ackley, A.Casey (Monash U.)
V.Dhillon, M.Dyer, S.Littlefair, E.Daw, J.Mullaney, L.Makrygianni, J.Maund (U. Sheffield)
S.Poshyachinda, S.Aukkaravittayapun, U.Sawangwit, S.Awiphan, D.Mkrtichian (NARIT)

report on behalf of the GOTO collaboration:


The Gravitational-wave Optical Transient Observer observed the field of GRB 171205A (trigger=794972, D'Elia et al. GCN Circ. 22177) from Roque de los Muchachos Observatory beginning at 2017-12-06T04:24:31 UT, 21.07 hours since burst, in several wide-band filters.

In a combined L-band image (400-700nm passband), with a total exposure time of 1440s at a mid-time 04:57:38 UT, 21.36 hours since burst, we detect the optical counterpart (Selsing et al. GCN Circ. 22180; Emery & D'Elia GCN Circ. 22181; Butler et al. GCN Circ. 22182; Mao et al. GCN Circ. 22186; Choi & Im GCN Circ. 22188) with a preliminary magnitude of V=18.95 +/- 0.15 based on a comparison to APASS V-band calibrators. Galaxy contamination is likely leading to an additional systematic uncertainty.
An image can be viewed here: www.arm.ac.uk/~gar/GRB171205A-goto.jpg<http://www.arm.ac.uk/~gar/GRB171205A-goto.tiff>


Further observations are scheduled.

GOTO is operated at the La Palma observing facilities of the University of Warwick on behalf of a consortium including the University of Warwick, Monash University, Armagh Observatory, the University of Leicester, the University of Sheffield, the National Astronomical Research Institute of Thailand (NARIT) and the Instituto de Astrofsica de Canarias (IAC)
(https://goto-observatory.org<https://goto-observatory.org/>)
GOTO Observatory<https://goto-observatory.org/>
goto-observatory.org
The first GOTO dome at Roque de Los Muchachos observatory on La Palma. About. The Gravitational-wave Optical Transient Observer (GOTO) is a project to identify ...


GRB_name: GRB171205A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22191
SUBJECT: Possible blackbody component in the X-ray spectrum of GRB171205A
DATE:    17/12/06 17:31:56 GMT
FROM:    Sergio Campana at INAF-OAB  <sergio.campana@brera.inaf.it>

S. Campana (INAF-OAB), A. Beardmore (U. Leicester), A. D'Ai (INAF-IASFPA),
V. D'Elia (ASDC), P. Evans (U. Leicester), J. Kennea (PSU), J.P. Osborne
(U. Leicester), K.L. Page (U. Leicester), R.L.C. Starling (U. Leicester)

report on a preliminary analysis of the Swift XRT data. Swift XRT started
observing GRB171205A (D'Elia et al. 2017, GCN 22177) 145 s after the 
trigger.
XRT detected a bright X-ray source decreasing from ~80 c/s to ~10 c/s
from 150 s to 400 s, remaining in Windowed Timing (WT) mode (Kennea et al.
2017, GCN 22183).
The hardness ratio light curve does not imply appreciable spectral
variations during this time interval.
We fit the WT spectrum binned to 20 counts per energy bin with an absorbed
power law (with the column density fixed to 5.9e20 cm-2, Willingale et al.
2013, MNRAS 431 394).
We obtain a reduced chi2=1.23 (239 degrees of freedom, dof, and 9e-3 null
hypothesis probability, nhp).
The inclusion of an intrinsic absorption component at the GRB redshift
(z=0.0368, Izzo et al. 2017, GCN 22180) does not improve the fit, rather
we can only put a 90% confidence level upper limit of N_H(z)<0.3e20 cm-2.

Given the relatively low nhp of the fit we include a soft blackbody 
component.
The fit improves considerably with kT_BB=0.10+-0.02 keV (90% c.l.) and
equivalent radius R_BB~5e11 cm (for a source distance of 163 Mpc).
The fit is good with a reduced chi2=1.09 (237 dof and 0.15 nhp).
F-test provides a probability for a chance improvement of 6e-8.
The 0.3-10 keV blackbody contribution to the total flux is ~4%.

We checked that the fit does not improve using different values for the
Galactic column density (NH_DL=4.82e20 cm-2 or NH_Kalberla=4.91e20
cm-2), reaching similar results.
Using a spectrum made from grade 0 events does not change the
results and the blackbody component is still significant.


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22192
SUBJECT: GRB 171205A: SMARTS optical/IR afterglow observations
DATE:    17/12/06 20:08:38 GMT
FROM:    Bethany Cobb at GWU  <bcobb@gwu.edu>

B. E. Cobb (GWU), reports:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained optical/IR imaging of the error region of GRB 171205A
(GCN 22177, D'Elia et al.) with a mid-exposure time of about
24.5 hrs post-burst (2017-12-06 07:50 UT). Total summed exposure
times amounted to 15 min in V and I and 12 min in J and K.

The afterglow of GRB 171205A (e.g. GCN 22179, Osborne et al.;
GCN 22180, Izzo et al.; GCN 22181, Emery et al.) was detected
with the following preliminary magnitudes:

V mag = 18.5 +/- 0.1
I mag = 17.7 +/- 0.1
J mag = 17.6 +/- 0.1
K mag = 16.2 +/- 0.1

(Optical photometry is calibrated against Landolt standard stars
and IR photometry is calibrated against 2MASS stars in the
field.)


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22193
SUBJECT: GRB 171205A: CHILESCOPE optical observations
DATE:    17/12/06 20:57:10 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI), A. Pozanenko (IKI),  E. Mazaeva (IKI),  M. Krugov 
(AFIF) report on behalf of IKI-GW follow-up collaboration:

We observed the field of GRB 171205A (D'Elia et al., GCN 22177)   with 
RC-1000 1m telescope of CHILESCOPE observatory. The observations carried 
out in a clear filter starting on Dec. 06 (UT) 06:46:47. The afterglow 
of GRB 171205A (e.g.  Osborne et al., GCN 22179;  Izzo et al., GCN 
22180; Emery et al., GCN 22181) is clearly detected.  Preliminary 
photometry is following.

Date       UT start   t-T0    Filter Exp.    OT     Err.
                       (mid, days)     (s)

2017-12-06 06:46:47  1.00122  CR     3600    18.20  0.07


The photometry is based on several nearby USNO-B1.0 stars (R2 magnitudes).

USNO-B1.0      RA          Dec         R2
0774-0291882  11:09:46.28 -12:35:02.8  17.25
0773-0296803  11:09:34.42 -12:37:07.2  16.58
0774-0291827  11:09:37.14 -12:32:33.8  16.45
0774-0291826  11:09:36.63 -12:34:12.4  16.40
0774-0291864  11:09:43.12 -12:33:49.8  16.30
0774-0291938  11:09:56.38 -12:35:37.7  16.40
0773-0296901  11:09:57.46 -12:36:29.0  15.34

Finding chart can be found at
http://grb.rssi.ru/GRB171205A/GRB171205_RC1000-171206.png


GRB_name: GRB171205A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22194
SUBJECT: GRB 171205A: Host galaxy photometric properties
DATE:    17/12/06 21:55:57 GMT
FROM:    Daniel Perley at Liverpool JMU  <d.a.perley@ljmu.ac.uk>

D. A. Perley and K. Taggart (LJMU) report:

We downloaded public, pre-explosion survey data covering the field of
GRB 171205A (D'Elia et al., GCN 22177) from a number of public archives:
GALEX (Martin et al. 2005, ApJL 619 1), Pan-STARRS 1 (Chambers et al.
2016, arXiv:1612.05560), and 2MASS (Skrutskie et al. 2006, 131 1163).
Photometry of the presumed host galaxy (2MASX J11093966-1235116; Izzo et
al., GCN 22178) was obtained from the relevant photometric catalogs for
2MASS (Huchra et al. 2012, ApJS 199 26) and GALEX (Bianchi et al. 2011,
MNRAS 411 2770).  For Pan-STARRS 1, we performed elliptical aperture
photometry on the images ourselves (using a semimajor axis of 19.35" and
axis ratio 0.6) using PS1 field stars for calibration.

We fit the combined SED (including 10 filters: GALEX FUV and NUV,
Pan-STARRS g, r, i, z, and y, and 2MASS J, H, and Ks) using the SED
fitting package LePHARE (Arnouts et al. 1999, MNRAS 310 540; Ilbert et
al. 2006, A&A 457 841).  A redshift of z=0.037 was assumed (Izzo et al.,
GCN 22180), and Galactic foreground extinction was taken to be
E(B-V)=0.045 (Schlafly et al. 2011; ApJ 737 103).  We obtain a stellar
mass of log10(M/Msun) = 10.1 +/- 0.1 and a star-formation rate of SFR =
3 +/- 1 Msun/yr.

This host mass is much larger than that of any other low-redshift GRB
with a confirmed SN counterpart.  The next-most-massive SN/GRB host is
that of GRB 120422A (SN 2012bz), with log10(M)~9.0.

In contrast, the majority of low-z (z<0.4) long-duration (>2s) GRBs with
no unambiguous observed SNe are in massive hosts similar to this event.
These include GRBs 060505 (Fynbo et al. 2006, Nature 444 1047), 051109B
(Perley et al., GCN 5387), 050219A (Rossi et al. 2014, A&A 572), 050826
(Mirabal et al. 2007, ApJ 661, 127), 080517 (Stanway et al. 2015, MNRAS
226 3911), and possibly 150518A (cf GCN 17903, Pozanenko et al).  In
many of these cases an SN was not searched for to deep limits, and
others could be attributed to host extinction, an ambiguous duration
possibly consistent with the "short" GRB class, or confusion of a high-z
GRB with a foreground galaxy.

Nevertheless, it remains possible that host mass (and perhaps
metallicity) is closely connected to whether a luminous SN emerges from
a GRB explosion.  The very long duration, bright UV counterpart, and
early spectroscopy of GRB 171205A all suggest that this is a genuine
(albeit low-luminosity) long GRB and is not extinguished or at high-z,
and it is in a high-mass galaxy (although its position is at the outer
edge of the disk).  Whether or not an SN emerges from this GRB
represents an important test of the tentative host dichotomy suggested
by previous events.  We encourage observers to monitor the photometric
evolution carefully over the coming days and obtain deep, multiband
photometry and spectroscopy, especially if a clear rising SN does not
emerge.

[GCN OPS NOTE(15dec17: Per author's request, the first-author Kann
reference was corrected to be Izzo.]


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22195
SUBJECT: GRB 171205A: GMG observations (2nd night)
DATE:    17/12/07 07:00:13 GMT
FROM:    Jirong Mao at Yunnan Obs  <jirongmao_obs@ynao.ac.cn>

J. Mao, X. Ding and J.-M. Bai (YNAO) report:


We observed the field of GRB 171205A (D'Elia et al., GCN 22177) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG)
station of Yunnan Observatories, beginning from 22:04:14 UT, 6th, Dec., 2017, about 1.6 days after the trigger. We still clearly detected the optical counterpart. Some preliminary results were roughly estimated as B~20.7, V~20.0, and R~20.7 mag. The brightness might be underestimated due to poor seeing. Although the magnitudes we measured have large uncertainty, we compare our observation of the first night (Mao et al. GCN 22186), and it seems that the source has no significant fading evidence.


GRB_name: GRB171205A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22196
SUBJECT: GRB171205A hyperluminal radio afterglow?
DATE:    17/12/07 11:28:34 GMT
FROM:    Arnon Dar at Technion-Israel Inst. of Tech  <arnon@physics.technion.ac.il>

Dado, Dar and De Rujula report:

The very bright radio afterglow^1 of the far off-axis (low luminosity)
GRB171205A at the outskirts of its host galaxy^2 at redshift z=0.0368
(agular distance Da~ 150 Mpc), provides another rare opportunity, like
GRBs^3 980425 and 030329, to measure the apparent hyperluminal separation
of the jet-produced afterglow from the anticipated supernova, which
launched it^3. The CB model relation Ep \propto Eiso^{1/3} for far 
off-axis GRBs^4, and its estimated isotropic energy release in the 
observed 15-150 keV band^5, Eiso~ 5.7E49 erg, yield, in the CB model^3, 
Ep~100 keV, viewing angle of @~(2/Ep(eV))^1/2~4.5 mrad, and a hyperluminal
velocity^3 V~ 2c/@ ~450c.

With such a hyperluminal velocity, the radio afterglow separation from the
SN, which launched it, will reach ~ 200 mas! after a year, easily resolved 
in VLBI and VLA radio follow-up observations.

If the afterglow of GRB171205A was a SN-less^6 GRB, produced by a highly
relativistic jet launched in a phase transition of a neutron star
(to quark star ?), the above estimate will not be valid for the separation
of the radio afterglow from the GRB position, if its late-time afterglow
was produced by a highly magnetized millisecond pulsar^7 (MSP).

We strongly urge VLA and VLBI follow up observations of the radio 
afterglow of GRB171205A.

1. A. de Ugarte Postigo, et al. GCN 22187
2. L. Izzo, et al. GCN 22180
3. S. Dado, A. Dar and A. De Rujula, arXiv:1610.01985
4. S. Dado and A. Dar, arXiv:1708.04603
5. S. D. Barthelmy, et al. GCN 22184
6. D. A. Perley and K. Taggart GCN 22194
7. S. Dado, A. Dar  arXiv:1710.02456


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22197
SUBJECT: GRB 171205A: LCO 1-m telescope observations
DATE:    17/12/07 13:36:16 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell (U. Bath), 
A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU) on behalf of a large 
collaboration report:

We observed Swift GRB171205A (D'Elia et al. GCN 22177) on December 7, 
07:21 UT (2.0 days post burst) with one of the 1-m LCO telescopes in 
Cerro Tololo in the SDSS ri filters. We clearly detect the optical 
afterglow (Izzo et al. GCN 22180; Emery et al. GCN 22181; Butler et al. 
GCN 22182; Mao et al. GCN 22186; Choi et al. GCN 22188; Melandri et al. 
GCN 22189; Steeghs et al. GCN 22190; Cobb et al. GCN 22192; Volnova et 
al. GCN 22193) with the following magnitudes:

Mid Time Exposure Filter Magnitude (AB)
(days) (s)
-------------------------------------------------------
2.0 5x120 SDSS-R 19.43 +- 0.10
2.0 5x120 SDSS-I 19.19 +- 0.10
-------------------------------------------------------

as calibrated against nearby Pan-STARRS objects.


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22198
SUBJECT: GRB 171205A: GROND observations of the optical/NIR transient
DATE:    17/12/07 14:42:34 GMT
FROM:    Sebastian Schmidl at TLS Tautenburg  <schmidl@tls-tautenburg.de>

S. Schmidl (TLS Tautenburg) and P. Schady (MPE Garching) report:

We observed the field of GRB 171205A (Swift trigger 794972; D'Elia et al.,
GCN 22177) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla
Observatory (Chile).

Observations started at 07:30 UT on December 05, 2017, 10 minutes after
the GRB trigger. They were performed at an average seeing of 1.5" and at
an average airmass of 1.5.

We clearly detect the optical/NIR transient of GRB 171205A (Izzo et al.,
GCN 22180; Emery & D'Elia, GCN 22181; Butler et al., GCN 22182; Mao et
al., GCN 22186; de Ugarte Postigo et al., GCN 22187; Choi et al., GCN
22188; Melandri et al., GCN 22189; Steeghs et al., GCN 22190; Cobb et al.,
GCN 22192; Volnova et al., GCN 22193; Guidorzi et al., GCN 22197).

Based on total exposures of 66 seconds in g'r'i'z', 60 seconds in JH and
180 seconds in K at a midtime of 0.36 hours after the burst, we measure
the following preliminary magnitudes and upper limits (AB magnitude
system):

g' = 19.1 +/- 0.1 mag,
r' = 18.9 +/- 0.1 mag,
i' = 18.9 +/- 0.1 mag,
z' = 18.8 +/- 0.1 mag,
J  = 18.4 +/- 0.2 mag,
H  = 18.2 +/- 0.3 mag, and
K  > 17.6 mag.

Magnitudes and upper limits are calibrated against PanSTARRS and 2MASS
field stars and are not corrected for the Galactic foreground extinction
corresponding to a reddening of E_(B-V)= 0.05 mag in the direction of the
burst (Schlegel et al. 1998).

Observations are continuing.


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22199
SUBJECT: GRB 171205A: MASTER-SAAO optical observations of unusual OT 
DATE:    17/12/07 16:35:25 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, D.Kuvshinov, A.V.Krylov,
I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko
Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU

D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias

R.Podesta, C.Lopez, F. Podesta Observatorio Astronomico Felix Aguilar (OAFA),
National University of San Juan, Argentina

H. Levato, C. Saffe
Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE),
San Juan, Argentina

O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk,
Irkutsk State University

V.Yurkov, Yu.Sergienko
Blagoveschensk Educational State University, Blagoveschensk

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

MASTER-SAAO telescope observed Swift GRB171205A (D'Elia et al., GCN Circ. 
22177) since 2017-12-06 23:53:47UT.

There were 20 images with 180s exposition in B and unfiltered (W=0.2B+0.8R 
calibrated by USNO-B1) .

MASTER-SAAO auto-detection system detected optical transient ((Izzo et 
al. GCN 22180; Emery et al. GCN 22181; Butler et al. GCN 22182; Mao et al. 
GCN 22186; Choi et al. GCN 22188; Melandri et al. GCN 22189; Steeghs et 
al. GCN 22190; Cobb et al. GCN 22192, Schmidl et al. GCN22198) several 
filters. The unfriltered magnitude is about ~ 19.4 mag .

We note that absolute magnitude is about -16.5.

The dicovery image is available at 
http://observ.pereplet.ru/images/MASTERGRB171205A.jpg


This message can be cited.


GRB_name: GRB171205A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22202
SUBJECT: GRB 171205A: Continued Swift/UVOT Observations
DATE:    17/12/07 17:40:15 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>

M. H. Siegel (PSU), P. J. Brown (Mitchell Institute, TAMU), 
S.W.K. Emery (UCL-MSSL) and V. D'Elia (ASDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT has continued observations of the optical transient in
GRB 171205A (Dâ€™Elia et al., GCN Circ. 22177).  We find that photometry
in the optical passbands is consistent with either steady flux or slight
decline, consistent with the report of Mao et al. (GCN Circ. 22195).  However,
all four UV passbands show a significant decay over the first day of
observations.  Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:

Filter  T_start(s)   T_stop(s)   Exp(s)      Mag


white       155       3850       183     18.05+-0.07
white      5524      28415      1081     17.85+-0.05
white    188009     193590       703     18.58+-0.08
v          5934      22497       903     18.09+-0.08
v         46094      57628       150     18.26+-0.24
v         74068     142426       350     18.20+-0.12
b          3608       3808       196     18.69+-0.10
b         26595      27502       885     18.53+-0.06
b         38171      61189       254     18.43+-0.08
b         67064     141691       379     18.69+-0.08
u           312        391        77     17.75+-0.18
u         16032      16558       513     17.54+-0.06
u         38114      61132       254     17.66+-0.08
u         67030     141669       379     18.32+-0.09
uvm2       9466      10366       885     16.67+-0.06
uvm2      46150      57780       435     18.37+-0.15
uvm2      74102     142498      1315     18.71+-0.11
uvw1      10373      16025      1066     16.95+-0.06
uvw1      38031      61074       383     17.93+-0.10
uvw1      66981     141647       568     18.51+-0.11
uvw2       5729      28438      1098     17.06+-0.07
uvw2      40218     141597      2322     18.68+-0.08
uvw2      73989     142404       877     18.82+-0.12

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 in the direction of the burst
(Schlegel et al. 1998), nor from any contribution of the host galaxy.


GRB_name: GRB171205A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22204
SUBJECT: GRB 171205A: Detection of the emerging SN
DATE:    17/12/07 18:13:58 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), L. Izzo (HETH/IAA-CSIC),
D.A. Kann (HETH/IAA-CSIC), C.C. Thoene (HETH/IAA-CSIC), P. Pesev (GTC),
R. Scarpa (GTC), D. Perez (GTC) report on behalf of a larger collaboration:

We have been monitoring the counterpart of GRB 171205A (D'Elia et al. 
GCN22177; Izzo et al., GCN 22180) photometrically and spectroscopically 
with OSIRIS at the 10.4m GTC telescope. Our latest observation consisted of 
3x600s exposure using the R1000B grism, which covers the spectral range 
between 3700 and 7880 Angstrom. On the combined spectrum, with epoch on 
the 7th of December at 6:05 UT, we detect broad undulating spectral features, 
which are prominent between 4000 and 6000 Angstrom, superposed to the 
afterglow continuum, which seem to indicate the emergence of an underlying 
supernova component. The features include a double bump in this range, 
similar to what was seen for the very early spectra of SN 1998bw (Patat et al. 
2001), indicating that this is probably also a broad line Ic supernova.

Further information will be provided through the TNS.


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22205
SUBJECT: GRB 171205A: TSHAO optical observations
DATE:    17/12/07 19:30:56 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI), A. Pozanenko (IKI),  E. Mazaeva (IKI),  M. Krugov (FAPHI), 
I. Reva (FAPHI),  A. Kusakin (FAPHI),   report on behalf of  larger GRB 
follow-up collaboration:

We observed the field of GRB 171205A (D'Elia et al., GCN 22177)   with 
Zeiss-1000 1-m telescope of Tien Shan Astronomical Observatory starting on 
Dec. 06 (UT) 22:2319. We took several images in R-filter.  The afterglow of 
GRB 171205A (Izzo et al. GCN 22180; Emery et al. GCN 22181; Butler et al. 
GCN 22182; Mao et al. GCN 22186; Choi et al. GCN 22188; Melandri et al. GCN 
22189; Steeghs et al. GCN 22190; Cobb et al. GCN 22192; Volnova et al. GCN 
22193; Guidorzi et al. GCN 22197; Schmidl et al. GCN 22198; Lipunov et al. 
GCN 22199;  Ugarte Postigo et al. GCN 22204)  is marginally detected. 
Preliminary photometry is following.

Date              UT start    t-T0         Filter Exp.    OT     Err.
                       (mid, days)                       (s)

2017-12-06  22:23:19 1.63574  R     1500    20.4  0.3


The photometry is based on several nearby USNO-B1.0 stars previously used in 
GCN 22193. 


GRB_name: GRB170817A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22206
SUBJECT: LIGO/Virgo G298048: Brightening X-ray Emission from GW170817/GRB170817A/SSS17a 
DATE:    17/12/07 22:11:17 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

Daryl Haggard, John J. Ruan, Melania Nynka (McGill/MSI), Vicky Kalogera (Northwestern/CIERA), and Phil Evans (Leicester) report:

We have performed a detailed analysis of new Chandra X-ray observations of GW170817 obtained via Chandra Director's Discretionary Time (PI: Wilkes, Program Number 18408601). The X-ray counterpart to GW170817/GRB170817A/SSS17a is clearly detected in the new observations.

This program acquired two exposures of GRB170817A: (1) a 74.09 ks exposure (ObsID 20860) beginning at 2017 December 2.08 UT, approximately 108 days post-burst, and (2) a 24.74 ks exposure (ObsID 20861) beginning at 2017 December 6.45 UT, approximately 111 days post-burst. Since the two new exposures are close in time and the X-ray emission of GRB170817A is not expected to vary significantly over ~4 day timescales, we co-add the two data sets into one 98.83 ks exposure at 109.2 days post-burst.

We perform spectral extractions assuming an absorbed power-law spectral model with fixed NH = 7.5e20 cm^âˆ’2 and find that the X-ray flux of GRB170817A has an absorbed flux of f(0.3âˆ’8 keV) = 1.58eâˆ’14 +/- 0.14 erg s^âˆ’1 cm^âˆ’2  (Gamma = 1.62 +/- 0.27) at 109.2 days post-burst, which corresponds to an unabsorbed luminosity of L(0.3âˆ’10 keV) = 42.5e38 +/- 3.7 erg s^âˆ’1 (see also Troja et al. GCN 22201 and Margutti et al. GCN 22203). This represents significant X-ray brightening compared to Chandra observations at 15.6 days post-burst, for which we find an absorbed flux of f(0.3âˆ’8 keV) = 0.36eâˆ’14 +/- 0.1 erg s^âˆ’1 cm^âˆ’2 (Gamma = 2.4 +/- 0.8) and an unabsorbed luminosity of L(0.3âˆ’10 keV) = 10.4e38 +/- 2.0 erg s^âˆ’1 (Haggard et al. 2017).

We also examine the three previously-detected X-ray sources CXOU J130948, CXOU 130946, and the host galaxy NGC 4993. The fluxes of CXOU 130946 and the host-galaxy NGC 4993 are consistent with our previous deep Chandra observations, while CXOU J130948 appears to be variable in X-rays (Margutti et al. 2017; Haggard et al. 2017).

The origin of the X-ray emission from the NS-NS coalescence GW170817/GRB170817A is an important diagnostic for all post-merger interpretations, and different scenarios predict distinct evolution in its X-ray light curve. These observations support scenarios in which the X-ray and radio emission share a common origin, i.e., the X-ray light curve is consistent with outflow models which may be either a cocoon shocked by the jet or dynamical ejecta from the merger. Further deep X-ray monitoring can place powerful constraints on the physical parameters of these models. The X-ray brightening strengthens the argument that simple top-hat jet models are not consistent with the latest observations. However, more advanced models of structured jets with off-axis viewing angles should be pursued and cannot yet be ruled out.

We thank Belinda Wilkes and the Chandra scheduling, data processing, and archive teams for making these observations possible.


GRB_name: GRB171106A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22208
SUBJECT: GRB 171106A CALET Gamma-Ray Burst Monitor detection
DATE:    17/12/08 00:23:47 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

M. Moriyama, A. Yoshida, T. Sakamoto, Y. Kawakubo, Y. Yamada,
A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 171106A (Fermi-GBM trigger #531662214,
INTEGRAL SPI-ACS trigger #7958, Konus-Wind trigger time on 11:56:50.118) triggered
the CALET Gamma-ray Burst Monitor (CGBM) at 11:56:48.57 on 6 November 2017.
The burst signal was seen by the all CGBM instruments.

The light curve of the SGM shows several peaks.  The emission starts at T+2 sec,
peaks at T+4 sec and ends at T+13.5 sec.  The weak 2nd and 3rd peaks are visible at
T+7 sec and T+12 sec.  The T90 duration measured by the SGM data is
1.8 +- 0.2 sec (40-1000 keV).

The light curve is available at

http://yoshidalab.mydns.jp/cgbm_trigger/flight/1194004517/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB171120A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22209
SUBJECT: GRB 171120A CALET Gamma-Ray Burst Monitor detection
DATE:    17/12/08 00:27:12 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

Y. Yamada, A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama,
A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu,
T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 171120A (Tohuvavohu et al., GCN circ. 22133; Longo et al.,
GCN circ. 22136; Frederiks et al., GCN circ. 22142; Sharma et al., GCN circ. 22143;
Li et al., GCN circ. 22149) triggered the CALET Gamma-ray Burst Monitor (CGBM)
at 13:20:02 on 20 November 2017.  The burst signal was seen by the all CGBM
instruments.

The light curve of the SGM shows two largely separated episodes.  The first
episode starts at T0, peaks at T+1 sec and ends at T+4 sec.  The second
episode starts T+38 sec, peaks at T+40 sec and ends at T+46 sec.
The T90 duration measured by the SGM data is 44.4 +- 0.9 sec (40-1000 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1195219087/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB171124A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22210
SUBJECT: GRB 171124A CALET Gamma-Ray Burst Monitor detection
DATE:    17/12/08 00:29:41 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

A. Tezuka, A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama, Y. Yamada,
S. Matsukawa (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU),
Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
W. Ishizaki (ICRR), M. L. Cherry (LSU), S. Ricciarini (U of Florence),
A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 171124A (Longo et al., GCN circ. 22156; Bissaldi et al.,
GCN circ. 22164; Sharma et al., GCN circ. 22168; Li et al., GCN circ. 22171) triggered
the CALET Gamma-ray Burst Monitor (CGBM) at 05:37:55.34 on 24 November 2017.
The burst signal was only seen by the SGM instrument.

The light curve of the SGM shows several peaks.  The emission starts
at T0, peaks at T+9 sec and ends at T+21 sec.  The T90 duration measured
by the SGM data is 17.8 +- 0.5 sec (40-1000 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1195536953/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB171209A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22212
SUBJECT: Swift Trigger 796098 is probably a noise peak near M31
DATE:    17/12/09 15:02:58 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

P. D'Avanzo (INAF-OAB), J.D. Gropp (PSU), J. A. Kennea (PSU),
S. J. LaPorte (PSU), A. Y. Lien (GSFC/UMBC), A. Melandri (INAF-OAB)
and D. M. Palmer (LANL) report on behalf of the Swift Team:

At 14:29:45 UT on 2017-09-17, the Swift Burst Alert Telescope (BAT) was 
observing the bright source Swift J0243.6+6124 .  The pulsations from 
this bright source cause BAT to trigger and image continuously while 
it is in the FOV. In one of these images, there was a low-significance 
(5.97 sigma) peak in the image within the boundaries of M31.  

The BAT on-board software has lowered thresholds in the regions around nearby 
galaxies. As a result, BAT reported this image peak and attempted an automated
follow-up.  Due to the Earth limb constraint, Swift could not immediately
observe the location. 
The BAT on-board calculated location is 
RA, Dec 12.177, +40.635 which is 
   RA(J2000) = 00h 48m 42s
   Dec(J2000) = +40d 38' 07"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty). 

We do not believe this is a true source.  We may make follow-up observations
with XRT as time permits to verify that this.  However, this will be of
lower priority than GRB 171209A which occurred a few minute later. 


GRB_name: GRB171209A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22213
SUBJECT: GRB 171209A: Swift detection of a burst
DATE:    17/12/09 15:30:16 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

S. J. LaPorte (PSU), D. N. Burrows (PSU), P. D'Avanzo (INAF-OAB),
S. W. K Emery (UCL-MSSL), J.D. Gropp (PSU), J. A. Kennea (PSU),
N. P. M. Kuin (UCL-MSSL), A. Melandri (INAF-OAB) and
D. M. Palmer (LANL) report on behalf of the Swift Team:

At 14:46:16 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 171209A (trigger=796100).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 139.382, -30.528 which is 
   RA(J2000) = 09h 17m 32s
   Dec(J2000) = -30d 31' 38"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 100 sec.  The peak count rate
was ~1300 counts/sec (15-350 keV), at ~80 sec after the trigger. 

UVOT took a finding chart exposure of 194 seconds with the U filter starting
265 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 25% of the
BAT error circle. The typical 3-sigma upper limit has been about 19.2 mag. The
8'x8' region for the list of sources generated on-board covers 98% of the BAT
error circle. The list of sources is typically complete to about 18.0 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.15. 
However, a possible candidate source of magnitude 17.3 in white is present at 
   RA(J2000) =  09h 17m 36.70s
   Dec(J2000) = -30d 31m 12.0s
which is very close to two other sources in the DSS survey image. 

The XRT detected the afterglow from this GRB.  However, due to data 
transmission problems, an XRT position will not be available until
more data is transmitted to the ground. 

Burst Advocate for this burst is S. J. LaPorte (extragsam 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: GRB171209A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22214
SUBJECT: GRB 171209A: LCO 1-m telescope observations
DATE:    17/12/09 18:11:27 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell (U. Bath), 
A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU) on behalf of a large 
collaboration report:

We observed Swift GRB171209A (LaPorte et al. GCN 22213) on December 9, 
16:25 UT (1.65 hours post burst) with one of the 1-m LCO telescopes in 
Siding Springs in the SDSS ri filters. We detect the UVOT candidate, 
which is not visible in archival Pan-STARRS images, with the following 
magnitudes:

Mid Time     Exposure        Filter     Magnitude (AB)
(hr)           (s)
------------------------------------------------------
1.69          2x120          SDSS-R       18.2 +- 0.3
1.78          2x120          SDSS-I       17.8 +- 0.3
------------------------------------------------------

as calibrated against nearby Pan-STARRS objects. Due to the vicinity of 
(~4") of a bright object, our estimated magnitudes are to be taken 
cautiously.


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22215
SUBJECT: GRB 171205A: UKIRT near-IR observations
DATE:    17/12/09 18:18:33 GMT
FROM:    Tanmoy Laskar at UC Berkeley  <tanmoylaskar@gmail.com>

T. Laskar (NRAO / UC Berkeley), W.Fong (Northwestern University), P. Milne,
and N. Smith (University of Arizona) report:

"We observed GRB 171205A (D'Elia et al., GCN 22177) with the Wide Field
Camera (WFCAM) mounted on the 3.8-m United Kingdom Infrared Telescope
(UKIRT) on Mauna Kea beginning on 2017 December 8.595 UT (3.29 days
post-burst) in the J- and K-bands. Using the quick-look pipeline ORAC-DR,
we clearly detect the near-IR counterpart, consistent with the XRT and
optical position (Osborne et al.; GCN 22179, Izzo et al.; GCN 22180, Emery
et al.; GCN 22181). We estimate the following preliminary photometry at the
position of the near-IR afterglow, calibrated to 2MASS and converted to the
AB system:

J(AB) = 18.5 +/- 0.1 mag
K(AB) = 18.3 +/- 0.1 mag

We note that these magnitudes may have a non-negligible contribution from
the host galaxy. Further observations are planned to track the brightness
evolution and determine the galaxy contribution. We thank Watson Varricatt
and Sam Benigni for their assistance in planning and executing these
observations."


GRB_name: GRB171205A
Detection_method: VLA Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22216
SUBJECT: GRB 171205A: VLA detection
DATE:    17/12/09 18:19:01 GMT
FROM:    Tanmoy Laskar at UC Berkeley  <tanmoylaskar@gmail.com>

T. Laskar (NRAO / UC Berkeley), D. L. Coppejans, R. Margutti (Northwestern
University), and K. D. Alexander (Harvard) report on behalf of a larger
collaboration:

"The VLA observed GRB 171205A (D'Elia et al.; GCN 22177) at multiple
frequencies from 4.49 GHz to 16.38 GHz beginning on 2017 December 9.58 UT
(4.3 days after the burst). At a mean frequency of 6 GHz, we detect a radio
source with a preliminary flux density of ~ 3 mJy at

RA = 11:09:39.5182 +/- 0.0001
Dec = -12:35:18.480 +/- 0.002

consistent with the Swift/XRT position (Osborne et al.; GCN 22179) and the
optical position (Izzo et al.; GCN 222180, Emery et al.; GCN 22181). The
spectral index is steeply rising to higher frequencies as nu^2, suggesting
a self-absorbed spectrum. Follow-up observations are planned. We thank the
VLA staff for rapidly scheduling and executing these service observations."


GRB_name: GRB171209A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22218
SUBJECT: GRB 171209A: Enhanced Swift-XRT position
DATE:    17/12/09 19:57:15 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. Dâ€™Avanzo, A. Melandri (INAF-OAB), J. A. Kennea (PSU), P.A. Evans 
and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team:

Using 2454 s of XRT Photon Counting mode data and 6 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 = 139.40280, -30.52016 which is equivalent to:

RA (J2000):  09 17 36.67
Dec (J2000): -30 31 12.6

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

This position is consistent with the one reported for the Swift/UVOT 
candidate (LaPorte et al., GCN 22213). 

This position may be improved as more data are received.  The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions <http://www.swift.ac.uk/xrt_positions>. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and 
Evans et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB171209A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22219
SUBJECT: GRB 171209A: Swift-XRT refined Analysis
DATE:    17/12/09 22:25:41 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), S.L. Gibson (U.
Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), P.
D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A.
Tohuvavohu (PSU) and S.J. LaPorte report on behalf of the Swift-XRT
team:

We have analysed 6.3 ks of XRT data for GRB 171209A (LaPorte et al. GCN
Circ. 22213), from 92 s to 17.9 ks after the  BAT trigger. The data
comprise 349 s in Windowed Timing (WT) mode (the first 5 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. Using 2454 s of PC mode data and 6 UVOT images, we find an
enhanced XRT position (using the XRT-UVOT alignment and matching UVOT
field sources to the USNO-B1 catalogue): RA, Dec = 139.40280, -30.52016
which is equivalent to:

RA (J2000): 09h 17m 36.67s
Dec(J2000): -30d 31' 12.6"

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=1.87 (+/-0.08). At T+231 s  the decay
steepens to an alpha of 3.42 (+0.26, -0.22) before breaking again at
T+629 s to a final decay with index alpha=0.74 (+0.12, -0.11).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.37 (+/-0.04). The
best-fitting absorption column is  2.54 (+0.27, -0.25) x 10^21 cm^-2,
in excess of the Galactic value of 2.1 x 10^21 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.06 (+0.08, -0.07)
and a best-fitting absorption column consistent with the Galactic
value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.4 x 10^-11 (4.5 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.11 (+0.10, -0.00) x 10^21 cm^-2
Galactic foreground: 2.1 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:      2.06 (+0.08, -0.07)

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 0.036 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x
10^-12 (1.6 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00796100.

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


GRB_name: GRB171209A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22221
SUBJECT: GRB 171209A: Swift/UVOT Analysis of the burst
DATE:    17/12/10 02:13:55 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and and S. J. LaPorte (PSU) report on
behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 171209A
107 s after the BAT trigger (LaPorte et al., GCN Circ. 22213).
The proposed possible transient position was confirmed by independent
observations of the LCO telescopes in Siding Springs in the SDSS r and
i filters (Guidorzi et al, GCN Corc. 22214) and by the XRT (d'Avanzo
et al. GCN Circ. 22218).

Due to the nearby star (at 3.7"), the count rates were determined using
a smaller than normal aperture of 2.5 arcsec, and for the reported
magnitudes no aperture correction has been applied.
The brightness is seen to rise to 16th magnitude around 400s past the
trigger at which time there is a break in the UVOT observations until
4000s past the trigger at which time the source is seen to be decaying.
After binning the white filter data in 10s bins, half a magnitude large
variability is seen up to 175s after the trigger.
There is no measurable flux in the uvw1,uvm2, and uvw1 filters
which were observed after the gap, which suggests a redshifted source
with a redshift in the range z = 1.8 - 2.8.

Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white              175          185          541         17.4
v                 4630         6265          393         17.3
b                 4014         5649          393         18.2
u                  320          350           30         16.5
w1                5039         6480          201         >19.6
m2                4834         6470          393         >20.2
w2                4425         6060          393         >20.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.15 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB171205A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22222
SUBJECT: GMRT upper limit on GRB 171205A
DATE:    17/12/10 09:20:42 GMT
FROM:    Poonam Chandra at TIFR  <poonam@ncra.tifr.res.in>

Poonam Chandra (NCRA-TIFR, Stockholm University), A. J. Nayana 
(NCRA-TIFR), Dipankar Bhattacharya (IUCAA), S. Bradley Cenko (NASA) and
Alessandra Corsi (Texas Tech University) report:

We observed GRB 171205A (D'Elia et al., GCN Circ. 22177) with the Giant 
Metrewave Radio Telescope (GMRT) on 2017 Dec 10.07 UT at 1400 MHz band. 
Our preliminary analysis results in a non-detection. The 3-sigma upper 
limit on the GRB position (Laskar et al.  GCN 22216) is 180 uJy. This 
could be because the radio emission may be absorbed at low frequencies.
More detailed analysis of the data is in progress.

More observations are planned. We thank the GMRT staff to schedule the 
observations.


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22223
SUBJECT: GRB 171205A: SAO-RAS optical observations
DATE:    17/12/10 10:02:37 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI), A. Moskvitin (SAO RAS), A. Pozanenko (IKI) report on 
behalf of of larger GRB follow-up collaboration:

We observed the field of GRB 171205A (D'Elia et al., GCN 22177)   with 
Zeiss-1000  telescope of SAO-RAS Observatory starting on Dec. 09 (UT) 
01:07:09. We took several images in R-filter.  The afterglow of GRB 
171205A (Izzo et al. GCN 22180; Emery et al. GCN 22181; Butler et al. 
GCN 22182; Mao et al. GCN 22186; Choi et al. GCN 22188; Melandri et al. 
GCN 22189; Steeghs et al. GCN 22190; Cobb et al. GCN 22192; Volnova et 
al. GCN 22193; Guidorzi et al. GCN 22197; Schmidl et al. GCN 22198; 
Lipunov et al. GCN 22199;  Ugarte Postigo et al. GCN 22204)  is clearly 
detected. Preliminary photometry is following.

Date        UT start  t-T0    Filter Exp.    OT     Err.  UL
                      (mid, days)    (s)

2017-12-09  01:07:09 3.79078  R      22*300  18.60  0.04  22.5

The photometry is based on several nearby USNO-B1.0 stars previously 
used in GCN 22193.


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22224
SUBJECT: GRB 171205A: Mondy optical observations
DATE:    17/12/10 10:17:25 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI),  A. Pozanenko (IKI),  E. Klunko (ISTP), E. Mazaeva 
(IKI)  report on behalf of of larger GRB follow-up collaboration:

We observed the field of GRB 171205A (D'Elia et al., GCN 22177)    with
AZT-33IK telescope of Sayan observatory (Mondy).  We took several images 
in R-filter under non-optimal weathe conditions on Dec. 08 and fair 
condiotns on Dec. 09.  The afterglow of GRB 171205A (Izzo et al. GCN 
22180; Emery et al. GCN 22181; Butler et al. GCN 22182; Mao et al. GCN 
22186; Choi et al. GCN 22188; Melandri et al. GCN 22189; Steeghs et al. 
GCN 22190; Cobb et al. GCN 22192; Volnova et al. GCN 22193; Guidorzi et 
al. GCN 22197; Schmidl et al. GCN 22198; Lipunov et al. GCN 22199; 
Ugarte Postigo et al. GCN 22204)  is  detected on Dec. 09. Preliminary 
photometry is following.

Date        UT start  t-T0    Filter Exp.  OT     Err.  UL
                      (mid, days)    (s)

2017-12-08  21:18:28 3.59292  R      1200  n/d    n/d  18.5
2017-12-09  20:44:55 4.57936  R      3300  18.4   0.1  21.7

The photometry is based on several nearby USNO-B1.0 stars previously 
used in GCN 22193.


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22225
SUBJECT: GRB 171205A: iTelescope optical observations
DATE:    17/12/10 12:51:52 GMT
FROM:    Veli-Pekka Hentunen at Taurus Hill Obs,A95  <veli-pekka.hentunen@kassiopeia.net>

Veli-Pekka Hentunen and Markku Nissinen (Taurus Hill Observatory,
Varkaus, Finland) report:

We have observed GRB 171205A field at iTelescope observatory (Siding
Spring, Australia) using T32  0.43-m f/6.8 astrograph. The optical counterpart
was detected at the position RA 11:09:39.6 and DEC -12:35:18.5.

The following magnitudes were obtained from the observations using
NOMAD1 0774-0294483 (V=15.610) as a comparison star:

Date                 Tmid(UT)    Filter         Exp. time     Mag         Mag.Err.
2017-12-09     17:00:25      unfiltered   10x120s      18.1 CV    0.5
2017-12-09     17:29:30      V                5x120s      17.4           0.6

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GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22226
SUBJECT: GRB 171205A: MASTER-Net OT recent photometry 
DATE:    17/12/10 17:15:00 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, D.Kuvshinov, A.V.Krylov,
I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko
Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU

R.Podesta, C.Lopez, F. Podesta Observatorio Astronomico Felix Aguilar 
(OAFA),
National University of San Juan, Argentina

H. Levato, C. Saffe
Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE),
San Juan, Argentina

D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias

O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk,
Irkutsk State University

V.Yurkov, Yu.Sergienko
Blagoveschensk Educational State University, Blagoveschensk

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

MASTER Global Robotic Net (http://observ.pereplet.ru) observes Swift GRB 
171205A (D'Elia et al., GCN 22177) every night at
MASTER-Kislovodsk, MASTER-IAC, MASTER-SAAO .

The optical counterpart (Izzo et al. GCN 22180; Emery et al. GCN 22181; 
Butler et al.GCN 22182; Mao et al. GCN 22186; Choi et al. GCN 22188; 
Melandri et al.GCN 22189; Steeghs et al. GCN 22190; Cobb et al. GCN 22192; 
Volnova et

al. GCN 22193; Guidorzi et al. GCN 22197; Schmidl et al. GCN 22198; 
Lipunov et al. GCN 22199;  Postigo et al. GCN 22204)

preliminary photometry of last nights is the following

    Date          UT        Filter            OT

2017-12-09 00:40:04.45    B            18.6+-0.2
2017-12-09 01:41:23.53    B            18.5+-0.2
2017-12-10 04:42:29.82    B            18.2+-0.2
2017-12-10 05:50:48.67    V            17.20+-0.20
2017-12-10 06:11:24.21    B            17.80+-0.24
2017-12-10 06:22:41.40    B            17.68+-0.16
2017-12-10 06:22:41.40    B            17.32+-0.19

This message can be cited.


GRB_name: GRB171205A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22227
SUBJECT: Konus-Wind observation of GRB 171205A
DATE:    17/12/10 17:31:55 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 171205A (Swift-BAT trigger #794972: (D'Elia et al.,
GCN  22177; Barthelmy et al., GCN 22184; T0(BAT)= 07:20:43.893 UT)
was detected by Konus-Wind (KW) in the waiting mode.

A bayesian block analysis of the KW waiting mode data reveals a count
rate increase in the interval from ~T0(BAT)-50 s to ~T0(BAT)+95 s.
The detection significance in the combined G1+G2 light curve
(25-360 keV) is ~10 sigma (95 s scale) while no statistically
significant emission has been detected in the G3 band (360-1470 keV).

The KW light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB171205A/

The time-averaged 3-channel spectrum, measured from T0(BAT)-48.743 s
to T0(BAT)+42.521 s, is well fit by a simple power-law (PL) model
with the PL index 2.0 Â± 0.18, chi2 = 0.88 for 1 dof.
The burst fluence in the 20-1500 keV band is (7.8 Â± 1.6)x10^-6 erg/cm^2.

Assuming z = 0.0368 (Izzo et al., GCN 22180) and a standard cosmology
model with H_0 = 70 km/s/Mpc, Omega_M = 0.30, and Omega_Lambda = 0.70, 
the burst isotropic energy release E_iso is 2.4x10^49 erg (20-1500 keV,
observer frame).

All the quoted errors are estimated at the 1 sigma confidence level.
All the presented results are preliminary.


GRB_name: GRB171210A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22228
SUBJECT: GRB 171210A: Fermi-LAT detection
DATE:    17/12/10 17:48:25 GMT
FROM:    Elisabetta Bissaldi at U.Innsbruk/IAPP  <Elisabetta.Bissaldi@uibk.ac.at>

E. Bissaldi (Politecnico & INFN Bari), F. Longo (Univ & INFN Trieste) 
and D. Kocevski (MSFC) report on behalf of the Fermi-LAT team:

"At 11:49:15.26 UT on December 10, 2017 Fermi-LAT detected high-energy emission from GRB 171210A, which was also detected by Fermi-GBM (trigger 534599360 / 171210493).

The best LAT on-ground location is found to be

RA, Dec = 335.29, 24.44 (J2000)

with an error radius of 0.15 deg (90 % containment, statistical error only). 

This was 50 deg from the LAT boresight at the time of the trigger and triggered an autonomous repoint of the spacecraft.

The data from the Fermi-LAT show a significant increase in the event rate that is spatially correlated with the trigger with high significance. 

The highest-energy photon is a 12 GeV event which is observed 1400 seconds after the GBM trigger.

A Swift ToO has been requested for this burst.

The Fermi-LAT point of contact for this burst is Elisabetta Bissaldi (Elisabetta.Bissaldi@ba.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."


GRB_name: GRB171209A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22229
SUBJECT: GRB 171209A: Swift-BAT refined analysis
DATE:    17/12/10 17:50:20 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

J. R. Cummings (CPI), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF/USRA), S. J. LaPorte (PSU),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-239 to T+400 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 171209A (trigger #796100)
(LaPorte et al., GCN Circ. 22213).  The BAT ground-calculated position is
RA, Dec = 139.387, -30.523 deg which is
  RA(J2000)  =  09h 17m 32.8s
  Dec(J2000) = -30d 31' 22.4"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 61%.

The mask-weighted light curve shows a multi-peaked structure that starts at
~ T-70 s and ends at ~ T+230 s. T90 (15-350 keV) is 161.7 +- 30.8 sec (estimated
error including systematics).

The time-averaged spectrum from T-70.76 to T+228.44 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.58 +- 0.07.  The fluence in the 15-150 keV band is 7.5 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+79.52 sec in the 15-150 keV band
is 1.6 +- 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/796100/BA/


GRB_name: GRB171209A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22230
SUBJECT: GRB 171209A: Lulin 1m telescope observations
DATE:    17/12/10 17:59:29 GMT
FROM:    Albert Kong at NTHU  <akhkong@gmail.com>

GRB 171209A: Lulin 1m telescope observations

A.K.H. Kong (NTHU, Taiwan) reports

We observed the field of GRB 171209A (LaPorte et al. GCN 22213) with
the 1m telescope at the Lulin Observatory in Taiwan. The observations
were done with the SDSS r and i filters and the first observation were
started at 2017-12-09 20:20:16 UT (5.6 hours post burst). We detect
the optical afterglow identified by the UVOT and LCO (Guidorzi et al.
GCN 22214). We obtained the following magnitudes:

Start time     Exposure     Filter     Magnitude (AB)
20:20:16       300s         SDSS-r     19.47+/-0.11
20:25:50       300s         SDSS-i     18.97+/-0.09

The magnitudes were calibrated with nearby Pan-STARRS objects.


GRB_name: GRB171205A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22231
SUBJECT: Correction to GCN 22184: GRB 171205A: Swift-BAT refined analysis
DATE:    17/12/10 19:31:23 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

A. Y. Lien (GSFC/UMBC) reports on behalf of the BAT team:

In the Swift-BAT refined analysis of GRB 171205A (Barthelmy et al. GCN Circ. 22184), 
we reported the incorrect Eiso for GRB 171205A due to a typo. The correct Eiso 
(in the observed 15-150 keV band) should be 1.10e+49 erg.

We apologize for the error, and we thank Dmitry Frederiks for pointing this out.


GRB_name: GRB171210A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22232
SUBJECT: GRB 171210A: Swift ToO observations
DATE:    17/12/10 20:59:17 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Swift has initiated a ToO observation of the Fermi/LAT GRB 171210A. 
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020785

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Fermi/LAT event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a 
GCN Circular after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

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


GRB_name: GRB171210A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22233
SUBJECT: GRB 171210A: Fermi GBM detection
DATE:    17/12/11 04:12:12 GMT
FROM:    Suraj Poolakkil at UAH  <sp0076@uah.edu>

S. Poolakkil (UAH), C. Meegan (UAH) and A. von Kienlin (MPE) report on
behalf of the Fermi GBM Team:

"At 11:49:15.26 UT on 10 December 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171210A (trigger 534599360 / 171210493)
which was also detected by the Fermi LAT (E. Bissaldi et al. 2017, GCN
22228). The GBM on-ground
location is consistent with the LAT position.

The trigger resulted in an Autonomous Repoint Request (ARR)
by the GBM Flight Software owing to the high peak flux of the GRB.
This ARR was accepted and the spacecraft slewed to the GBM in-flight
location. The initial angle from the Fermi LAT boresight to
the best location is 51 degrees.

The GBM light curve consists of a single bright peak
with a duration (T90) of about 143 s (50-300 keV).
The time-averaged spectrum from T0-1.02 s to T0+103.42 s is
best fit by a Band function with Epeak= 145 +/- 3 keV, alpha = -0.65 +/-
0.02
and beta = -2.34 +/- 0.05.

The event fluence (10-1000 keV) in this time interval is
(7.33 +/- 0.08)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+6.46 s in the 10-1000 keV band
is 16.7 +/- 0.36 ph/s/cm^2.

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


GRB_name: GRB171211A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22234
SUBJECT: GRB 171211A: Swift detection of a possibly short burst
DATE:    17/12/11 09:47:21 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@swift.psu.edu>

J.D. Gropp (PSU), A. P. Beardmore (U Leicester),
A. A. Breeveld (UCL-MSSL), P. D'Avanzo (INAF-OAB),
P. A. Evans (U Leicester), J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC)
and K. L. Page (U Leicester) report on behalf of the Swift Team:

At 09:27:32 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 171211A (trigger=796469).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 98.108, -58.670 which is 
   RA(J2000) = 06h 32m 26s
   Dec(J2000) = -58d 40' 10"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of about 3 sec.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 09:29:04.7 UT, 91.9 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source located at RA, Dec 98.13327, -58.69205 which
is equivalent to:
   RA(J2000)  = 06h 32m 31.98s
   Dec(J2000) = -58d 41' 31.4"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 92 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 8.89
x 10^20 cm^-2 (Willingale et al. 2013). 

There is no UVOT data available because of a bright source in the field of view. 

Burst Advocate for this burst is J.D. Gropp (jdg44 AT 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: GRB171210A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22235
SUBJECT: GRB 171210A: Swift-XRT and UVOT observations
DATE:    17/12/11 13:22:48 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

D.N. Burrows (PSU), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), A.P. Beardmore (U. Leicester), V. D'Elia (ASDC), A. D'Ai
(INAF-IASFPA), A. Melandri (INAF-OAB), A. Tohuvavohu (PSU), S. J.
LaPorte (PSU), P.A. Evans (U. Leicester), P. D'Avanzo (INAF-OAB) and 
N. P. M. Kuin (UCL-MSSL) report on behalf of the Swift team:

Swift-XRT has performed follow-up observations of the
Fermi/LAT-detected burst GRB 171210A (Bissaldi et al. GCN Circ. 22228),

collecting 5.0 ks of Photon Counting (PC) mode data between T0+34.7 ks
and T0+46.3 ks. 

Five uncatalogued X-ray sources have been detected, however none of
them is above the RASS limit or shows definitive signs of fading.
Therefore, at the present time we cannot identify which, if any, is the

afterglow. Details of these sources are given below:

Source 1:
  RA (J2000):  335.26545  =  22:21:3.71
  Dec (J2000): +24.47028  =  +24:28:13.0
  Error: 2.9 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: (7.5 [+1.5, -1.4])e-3 ct s^-1   
  Distance: 182 arcsec from Fermi/LAT position.
  Flux: (2.20 [+0.45, -0.41])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

This source lies 5.0" away from SDSS J222103.88+242817.4, which is
catalogued as a candidate quasar (Brescia et al., 2015, MNRAS, 450,
3893).

Source 2:
  RA (J2000):  335.2458  =  22:20:58.99
  Dec (J2000): +24.6016  =  +24:36:05.7
  Error: 5.7 arcsec (radius, 90% conf.)
  Count-rate: (2.23 [+0.98, -0.76])e-3 ct s^-1  
  Distance: 618 arcsec from Fermi/LAT position.
  Flux: (2.44 [+1.07, -0.83])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV)

This source lies 6.4" away from SDSS J222058.65+243610.1, which is
catalogued as a candidate quasar (Brescia et al., 2015, MNRAS, 450,
3893).

Source 3:
  RA (J2000):  335.4135  =  22:21:39.23
  Dec (J2000): +24.5534  =  +24:33:12.4
  Error: 7.0 arcsec (radius, 90% conf.)
  Count-rate: (3.01 [+1.11, -0.90])e-3 ct s^-1  
  Distance: 530 arcsec from Fermi/LAT position.
  Flux: (8.4 [+3.1, -2.5])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV)
This source lies 2.6" away from SDSS J222139.19+243314.9, which is
catalogued as a candidate quasar (Brescia et al., 2015, MNRAS, 450,
3893).

Source 4:
  RA (J2000):  335.42877  =  22:21:42.90
  Dec (J2000): +24.30996  =  +24:18:35.9
  Error: 2.4 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: 0.0137 +/- 0.0022 ct s^-1   
  Distance: 608 arcsec from Fermi/LAT position.
  Flux: (4.08 [+0.66, -0.64])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

This source lies 1.3" away from SDSS J222142.87+241837.0, which is
catalogued as a candidate quasar (Brescia et al., 2015, MNRAS, 450,
3893).

Source 5:
  RA (J2000):  335.37378  =  22:21:29.71
  Dec (J2000): +24.49242  =  +24:29:32.7
  Error: 2.3 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: (8.8 [+1.9, -1.8])e-3 ct s^-1   
  Distance: 281 arcsec from Fermi/LAT position.
  Flux: (3.00 [+0.65, -0.63])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

This source lies 1.7" away from SDSS J222129.58+242933.1, which is
catalogued as a candidate quasar (Brescia et al., 2015, MNRAS, 450,
3893).


The results of the XRT-team automatic analysis of the XRT observations,

including a position-specific upper limit calculator, are available at
http://www.swift.ac.uk/ToO_GRBs/00020785.


Simultaneous with the XRT, the UVOT observed the target region of GRB
171210A. Due to the smaller field of view, two of the candidate sources
(#2 and #4) are not on the UVOT image. The other candidate regions have
been examined but do not show any new sources. A further comparison of
the whole UVOT observation to the DSS survey shows no new sources. 

We acknowledge the use of the VizieR catalogue access tool, CDS,
Strasbourg, France.


This circular is an official product of the Swift team.


GRB_name: GRB171211A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22236
SUBJECT: GRB 171211A: Enhanced Swift-XRT position
DATE:    17/12/11 13:39:36 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 1720 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 171211A, 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 = 98.13542, -58.69209 which is equivalent
to:

RA (J2000): 06h 32m 32.50s
Dec (J2000): -58d 41' 31.5"

with an uncertainty of 2.8 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) and Evans
et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB171209A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22237
SUBJECT: GRB 171209A: MASTER-Net optical observations
DATE:    17/12/11 14:05:44 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

E. Gorbovskoy, V. Lipunov, V.Kornilov, N.Tyurina, 
D.Kuvshinov, A.V.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov, 
D. Vlasenko
Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU

R.Podesta, C.Lopez, F. Podesta Observatorio Astronomico Felix Aguilar (OAFA),
National University of San Juan, Argentina

H. Levato, C. Saffe
Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE),
San Juan, Argentina

D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias

O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk,
Irkutsk State University

V.Yurkov, Yu.Sergienko
Blagoveschensk Educational State University, Blagoveschensk

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory


MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in OAFA was starting survey on the SWIFT  GRB171209A error-box 
(LaPorte et al. GCN 22213)   44912 sec after notice time and 44965 sec 
after trigger time at 2017-12-10 03:15:41 UT. The 5-sigma upper limit on 
our single  (180s exposure)  set is about 19.4-m and  20.0-m on coadd 
(3x180 = 540s) image. We not see OT previously reported by Kuin et al. GCN 
22221 , Guidorzi et al. GCN 22214 ,  Kong et al. GCN 22230.


MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in SAAO  was starting survey on the SWIFT  GRB171209A   114607 
sec (~ 32 hours)  after trigger time at 2017-12-10 03:15:41 UT. The 
5-sigma upper limit on our single  (180s exposure)  set is about 19.4-m 
and  20.5-m on coadd (10 x 180 = 1800 s) image.  Here we also not see any 
OT.



This message can be cited.


GRB_name: GRB171210A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22238
SUBJECT: GRB 171210A: MASTER-Net optical observations 
DATE:    17/12/11 14:56:17 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

N.Tyurina, V. Lipunov, E. Gorbovskoy,V.Kornilov, D.Kuvshinov, 
A.V.Krylov,  I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko
Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU

R.Podesta, C.Lopez, F. Podesta Observatorio Astronomico Felix Aguilar (OAFA),
National University of San Juan, Argentina

H. Levato, C. Saffe
Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE),
San Juan, Argentina

D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias

O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk,
Irkutsk State University

V.Yurkov, Yu.Sergienko
Blagoveschensk Educational State University, Blagoveschensk

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory


MASTER-IAC robotic telescope (http://observ.pereplet.ru) started Fermi LAT 
GRB171210A  (Bissaldi et al. GCN 22228, t_trigger=2017-12-10 
11:49:15.26UT, RA, Dec = 335.29, 24.44 (J2000), 0.15deg (90%) 
stat.err.rad.) inspection at
2017-12-10 19:08:16UT (07h19m00.7s after trigger time) just after sunset.

The unfiltered mlim on the single images is 20.4 (180s exposition), and on 
the sum is 21m.

MASTER auto-detection System (Lipunov et al., 2010, Advances in Astronomy, 
vol. 2010, 30L)  didn't find optical counterpart.

http://observ.pereplet.ru/images/MASTERGRB171210AFermi.jpg


Observations were made on  zenit distance = 14 degrees, galaxy latitude b 
= -27 degree.

Dist. to Moon: 144.183815
Moon coord.: (176.084576 d, 5.105187 d
Lunar disk: 0.451595
Lunar phase: 95.555548
The sun  altitude  is -12.79


This message can be cited.


GRB_name: GRB171211A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22239
SUBJECT: GRB 171211A: Swift/UVOT Upper Limits
DATE:    17/12/11 17:01:01 GMT
FROM:    Sam Emery at MSSL-UCL  <samuel.emery.15@ucl.ac.uk>

S.W.K. Emery (UCL-MSSL) and J. D. Gropp (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 171211A
362 s after the BAT trigger (Gropp et al., GCN Circ. 22234).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 22236)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are:

Filter           T_start(s)   T_stop(s)      Exp(s)         Mag

v                    387         6321          491         >19.0
uvw1                 436         6731          491         >19.7
uvm2                5503         6526          393         >19.9
uvw2                 362         6939          668         >20.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.11 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB171211A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22240
SUBJECT: GRB 171211A: Swift-XRT refined Analysis
DATE:    17/12/11 19:06:04 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U.
Leicester), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo
(INAF-OAB), A. Tohuvavohu (PSU), S. J. LaPorte (PSU), J.A. Kennea (PSU)
and J.D. Gropp report on behalf of the Swift-XRT team:

We have analysed 7.4 ks of XRT data for GRB 171211A (Gropp et al. GCN
Circ. 22234), from 77 s to 24.5 ks after the  BAT trigger. The data
comprise 33 s in Windowed Timing (WT) mode (the first 8 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Beardmore
et al. (GCN Circ. 22236).

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.28 (+0.08, -0.07).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.60 (+0.27, -0.23). The
best-fitting absorption column is  1.3 (+1.0, -0.4) x 10^21 cm^-2,
consistent with the Galactic value of 8.9 x 10^20 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 4.3 x 10^-11 (4.9 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.3 (+1.0, -0.4) x 10^21 cm^-2
Galactic foreground: 8.9 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.60 (+0.27, -0.23)

If the light curve continues to decay with a power-law decay index of
1.28, the count rate at T+24 hours will be 6.6 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.8 x
10^-14 (3.3 x 10^-14) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00796469.

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


GRB_name: GRB171211A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22241
SUBJECT: GRB 171211A: Swift-BAT refined analysis
DATE:    17/12/11 23:19:15 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), J. D. Gropp (PSU),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
J. P. Norris (BSU), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 171211A (trigger #796469)
(Gropp et al., GCN Circ. 22234).  The BAT ground-calculated position is
RA, Dec = 98.154, -58.689 deg which is
  RA(J2000)  =  06h 32m 36.9s
  Dec(J2000) = -58d 41' 19.0"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 57%.

The mask-weighted light curve shows a single-peaked structure that starts and
peaks at ~ T0, and ends at ~T+3 s. T90 (15-350 keV) is 2.32 +- 0.59 sec
(estimated error including systematics).

The time-averaged spectrum from T+0.03 to T+2.70 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.77 +- 0.21.  The fluence in the 15-150 keV band is 2.4 +- 0.3 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.03 sec in the 15-150 keV band
is 2.3 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The duration and hardness of this burst show it to be intermediate between the
short and long burst populations.

Using a 64-ms binned light curve, the lag analysis finds a lag of
0.144 (+0.106, -0.066) s for the 50-100 keV to 15-25 keV band.
Despite the large error bars due to the weakness of this burst,
this value is more consistent with those of a long GRB.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/796469/BA/


GRB_name: GRB171205A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22242
SUBJECT: GRB 171205A: JCMT SCUBA-2 sub-mm observations
DATE:    17/12/12 03:03:28 GMT
FROM:    Ian Smith at Rice U  <ian@spacsun.rice.edu>

I.A. Smith (Rice U.) and N.R. Tanvir (U. of Leicester) report:

We are monitoring GRB 171205A (D'Elia et al., GCN Circ. 22177)
using the SCUBA-2 sub-millimeter continuum camera on the James 
Clerk Maxwell Telescope.  The source is well detected, as seen 
at longer wavelengths by NOEMA (de Ugarte Postigo et al., GCN 
Circ. 22187) and the VLA (Laskar et al., GCN Circ. 22216).
At 3.4 days after the burst trigger, the 850 micron flux density
was 30.3 +/- 2.4 mJy/beam.

We thank Mark Rawlings, William Montgomerie, Giovanni Rosotti,
Jim Hoge, and the JCMT staff for the prompt support of these 
observations that are being taken under project S17BP006.


GRB_name: GRB171212A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22243
SUBJECT: GRB 171212A: Swift detection of a burst or a Galactic transient
DATE:    17/12/12 12:21:26 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

A. Tohuvavohu (PSU), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), P. D'Avanzo (INAF-OAB), A. Deich (PSU),
S. W. K Emery (UCL-MSSL), P. A. Evans (U Leicester), J.D. Gropp (PSU),
J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL),
F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB),
K. L. Page (U Leicester), D. M. Palmer (LANL) and M. H. Siegel (PSU)
report on behalf of the Swift Team:

At 11:57:21 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 171212A (trigger=796778).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 293.900, +20.568 which is 
   RA(J2000) = 19h 35m 36s
   Dec(J2000) = +20d 34' 06"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 120 sec.  The peak count rate
was ~800 counts/sec (15-350 keV), at ~90 sec after the trigger. 

The XRT began observing the field at 11:58:52.7 UT, 91.0 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 293.91826,
20.59159 which is equivalent to:
   RA(J2000)  = 19h 35m 40.38s
   Dec(J2000) = +20d 35' 29.7"
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This
location is 104 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 1.23
x 10^22 cm^-2 (Willingale et al. 2013). 

The initial flux in the 2.5 s image was 1.28e-08 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 99 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 large, but uncertain, extinction expected. 

Because this event is very close to the Galactic plane (lat=0.03 degrees)
it is possibly a Galactic transient, in which case it takes the 
name 'Swift J1935.7+2036'. 

Burst Advocate for this burst is A. Tohuvavohu (aaronb AT swift.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: GRB171210A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22244
SUBJECT: Konus-Wind observation of GRB 171210A
DATE:    17/12/12 12:58:30 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

A.Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration GRB 171210A
(Fermi-LAT detection: Bissaldi et al., GCN 22228,
Fermi-GBM observation: Poolakkil et al., GCN 22233)
triggered Konus-Wind at T0=42556.704 s UT (11:49:16.704).

The burst light curve shows a single pulse
started at ~T0-6.1 s with a total duration of ~186.6 s.
The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst
had a fluence of 1.15(-0.10,+0.11)x10^-4 erg/cm2,
and a 64-ms peak flux, measured from T0+2.816 s,
of 7.85(-1.73,+1.79)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+140.544 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.76(-0.13,+0.15),
the high energy photon index beta = -2.42(-0.21,+0.14),
the peak energy Ep = 158(-14,+16) keV
(chi2 = 99/88 dof)

The spectrum near the maximum count rate
(measured from T0+0.256 to T0+5.376 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.64(-0.09,+0.11),
the high energy photon index beta = -2.83(-1.36,+0.40),
the peak energy Ep = 426(-46,+46) keV
(chi2 = 70/79 dof)

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB171210_T42556/

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


GRB_name: GRB171212A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22245
SUBJECT: GRB 171212A: Enhanced Swift-XRT position
DATE:    17/12/12 16:09:49 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 1519 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 171212A, 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 = 293.91782, +20.59204 which is equivalent
to:

RA (J2000): 19h 35m 40.28s
Dec (J2000): +20d 35' 31.3"

with an uncertainty of 2.3 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) and Evans
et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB171212A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22246
SUBJECT: GRB 171212A/Swift J1935.7+2036: TSHAO optical observations
DATE:    17/12/12 19:18:46 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), A. Pozanenko (IKI), I. Reva (FAPHI), M. Krugov 
(FAPHI), A. Kusakin (FAPHI), A. Volnova (IKI)   report on behalf of 
larger GRB follow-up collaboration:

We observed the field of GRB 171212A (Tohuvavohu  et al., GCN 22243) 
with Zeiss-1000 1-m telescope of Tien Shan Astronomical Observatory 
starting on Dec. 12 (UT) 12:21:15. We took several images in R-filter. 
Within enhanced Swift-XRT error circle   (Evans et al. GCN 22245)  we do 
not detect any object. Preliminary photometry of initial combined images 
is following.

Date        UT start    t-T0  Filter Exp.   OT   Err. ULim
                      (mid, days)     (s)

2017-12-12  12:21:15 0.01896  R      3*120  n/d  n/d  20.0
2017-12-12  12:21:15 0.02728  R     13*120  n/d  n/d  21.1


The photometry is based on several nearby USNO-B1.0 stars

USNO-B.1_id  R2
1105-0415742 17.60
1105-0415769 17.54
1105-0415805 16.38
1106-0408959 17.07
1105-0415666 16.91


GRB_name: GRB171212B
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22247
SUBJECT: GRB 171212B: Fermi-LAT detection
DATE:    17/12/12 22:00:25 GMT
FROM:    Giacomo Vianello at SLAC  <giacomov@slac.stanford.edu>

D. Kocevski (NASA/MSFC), F. Longo (Univ & INFN Trieste), E. Bissaldi
(Politecnico & INFN Bari), and G. Vianello (Stanford)

report on behalf of the Fermi-LAT team:

At 10:24:18.51 UT on December 12, 2017, Fermi-LAT detected
high-energy emission from GRB 171212B, which was also detected by
Fermi-GBM (trigger 534767063 / 171212434).

The best LAT on-ground location is found to be

RA, Dec = 39.44, -70.62 (J2000)

with an error radius of 0.39 deg
(90 % containment, statistical error only).

This was 11 deg from the LAT boresight at the time of the trigger.

The data from the Fermi-LAT show a significant increase in the event rate
that is spatially correlated with the trigger with high significance.
The highest-energy photon is a 931 MeV event which
is observed 544 seconds after the GBM trigger.

The Fermi-LAT point of contact for this burst is
Francesco Longo (francesco.longo@ts.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.


GRB_name: GRB171212A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22248
SUBJECT: GRB 171212A/Swift J1935.7+2036: Swift/UVOT Upper Limits
DATE:    17/12/12 22:16:30 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL) and A. Tohuvavohu (PSU) report on behalf of 
the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 171212A 99 
s after the BAT trigger (Tohuvavohu et al., GCN Circ. 22243).
No optical afterglow consistent with the enhanced XRT position (Evans et 
al., GCN Circ. 22245) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system 
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding 
chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            99          249          147         >20.3
u_FC               257          507          246         >19.8
white               99         5510          383         >20.8
v                  588         5921          235         >19.0
b                  513         6581          275         >20.1
u                  257         6536          468         >20.1
w1                 638         6331          236         >19.5
m2                5926         6125          197         >19.3
w2                 738         5716          216         >19.5

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 7.95 in the direction of the 
burst (Schlegel et al. 1998).


GRB_name: GRB171212B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22249
SUBJECT: GRB 171212B: Fermi GBM observation
DATE:    17/12/12 22:51:03 GMT
FROM:    Elisabetta Bissaldi at U.Innsbruk/IAPP  <Elisabetta.Bissaldi@uibk.ac.at>

E. Bissaldi (Politecnico & INFN Bari) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:


"At 10:24:18.51 UT on 12 December 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171212B (trigger 534767063 / 171212434),
which was also detected by the Fermi-LAT (Kocevski et al. 2012, GCN 22247).
The GBM on-ground location is consistent with the LAT position.

The angle from the Fermi LAT boresight at the GBM trigger time is 11 degrees.

The GBM light curve consists of a multipeak emission episode
with a duration (T90) of about 32 s (50-300 keV).
The time-averaged spectrum from T0 to T0+32 s is
adequately fit by a Band function with Epeak = 74 +/- 9 keV,
alpha = -0.95 +/- 0.13, and beta = -2.32 +/- 0.15.

The event fluence (10-1000 keV) in this time interval is
(5.744 +/- 0.3)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+27 s in the 10-1000 keV band
is 5.0 +/- 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: GRB171211A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22250
SUBJECT: GRB 171211A iTelescope observation
DATE:    17/12/13 03:50:35 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

Y. Kitaoka, T. Sakamoto (AGU)

We observed the field of GRB 171211A detected by Swift (Gropp et al., GCN Circ. 22234)
with the iTelescope.Net (http://www.itelescope.net) T27 (Planewave 27") telescope located
at the AstroCamp Observatory (Siding Spring Observatory, AU).  8 images of 60 sec exposures
were taken in the I filter starting from December 11 on 11:41:37 (UT) about 134 minutes after
the trigger and stopped on 11:54:45 (UT).  We do not detect the optical afterglow both in
the individual images and the stacked image at the X-ray afterglow position.  The estimated
five sigma upper limit of the combined image (total exposure of 480 sec) is ~17.2 using
the USNO-B1 catalog.


GRB_name: GRB171212A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22251
SUBJECT: GRB 171212A: Swift-XRT refined Analysis
DATE:    17/12/13 12:21:03 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), A. Melandri
(INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), S. J. LaPorte
(PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), S.L. Gibson (U.
Leicester) and A. Tohuvavohu report on behalf of the Swift-XRT team:

We have analysed 5.7 ks of XRT data for GRB 171212A (Tohuvavohu et al.
GCN Circ. 22243), from 81 s to 29.5 ks after the  BAT trigger. The data
comprise 347 s in Windowed Timing (WT) mode (the first 8 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Evans et
al. (GCN Circ. 22245).

The late-time light curve (from T0+5.1 ks) can be modelled with a
power-law decay with a decay index of alpha=1.2 (+0.4, -0.3).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.83 (+/-0.08). The
best-fitting absorption column is  4.73 (+0.23, -0.22) x 10^22 cm^-2,
in excess of the Galactic value of 1.2 x 10^22 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 8.1 x 10^-11 (1.9 x 10^-10) erg
cm^-2 count^-1. 

A summary of the WT-mode spectrum is thus:
Total column:      4.73 (+0.23, -0.22) x 10^22 cm^-2
Galactic foreground: 1.2 x 10^22 cm^-2
Excess significance: 26.2 sigma
Photon index:      1.83 (+/-0.08)

If the light curve continues to decay with a power-law decay index of
1.2, the count rate at T+24 hours will be 1.5 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x
10^-13 (2.8 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00796778.

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


GRB_name: GRB171205A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22252
SUBJECT: GRB 171205A: ALMA observations
DATE:    17/12/13 12:32:39 GMT
FROM:    Daniel Perley at Liverpool JMU  <d.a.perley@ljmu.ac.uk>

D. A. Perley (LJMU), S. Schulze (Weizmann), and A. de Ugarte Postigo
(HETH/IAA-CSIC, DARK/NBI) report on behalf of a larger collaboration:

We observed the millimeter afterglow of GRB 171205A (D'Elia et al., GCN
22177; de Ugarte Postigo, GCN 22187) using the Atacama Large
Millimeter/Submillimeter Array (ALMA).  Observations were taken using
the band 3 (92 GHz) and band 7 (340 GHz) receivers.  The band 3
observations were carried out between 2017-12-11 09:40-10:01 UT (6.10
days after trigger) and the band 7 observations were carried out between
10:02-11:04 UT (6.13 days after trigger).

In a preliminary reduction, the afterglow is strongly detected (S/N >
100) in both channels.  We estimate a flux density of 28 mJy at 92 GHz
and a flux of 16 mJy at 340 GHz, with calibration uncertainties of ~15%
and ~25%, respectively.  We expect these uncertainties to improve
significantly after a full reduction.  Further observations are planned.

We acknowledge the support of the ALMA staff in conducting these
observations rapidly, in particular Anita Richards, Andy Biggs, and
Eelco van Kampen.

________________________________
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GRB_name: GRB171212A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22253
SUBJECT: GRB 171212A/Swift J1935.7+2036: Swift-BAT refined analysis
DATE:    17/12/13 13:56:37 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
A. Tohuvavohu (PSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+1004 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 171212A (trigger #796778)
(Tohuvavohu et al., GCN Circ. 22243).  The BAT ground-calculated position is
RA, Dec = 293.920, 20.597 deg which is
  RA(J2000)  =  19h 35m 40.8s
  Dec(J2000) = +20d 35' 49.6"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 60%.

The mask-weighted light curve shows a multi-peaked structure that starts at
~ T-30 s and ends at ~T+100 s, with some weak emissions lasting till ~ T+370 s.
T90 (15-350 keV) is 320 +- 72 sec (estimated error including systematics).

The time-averaged spectrum from T-28.82 to T+371.18 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.23 +- 0.14.  The fluence in the 15-150 keV band is 3.4 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+90.68 sec in the 15-150 keV band
is 0.7 +- 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/796778/BA/


GRB_name: GRB171216A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22256
SUBJECT: GRB 171216A: Swift detection of a burst
DATE:    17/12/16 03:23:29 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

F. E. Marshall (NASA/GSFC), J. R. Cummings (NASA/UMBC),
A. Deich (PSU), J.D. Gropp (PSU), J. A. Kennea (PSU),
A. Y. Lien (GSFC/UMBC), K. L. Page (U Leicester) and
D. M. Palmer (LANL) report on behalf of the Swift Team:

At 03:06:59 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 171216A (trigger=797441).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 212.078, -50.473 which is 
   RA(J2000) = 14h 08m 19s
   Dec(J2000) = -50d 28' 22"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of ~20 sec.  The peak count rate
was ~600 counts/sec (15-350 keV), at ~4 sec after the trigger. 

The XRT began observing the field at 03:08:54.7 UT, 115.2 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source with an enhanced position: RA, Dec
211.9924, -50.4851 which is equivalent to:
   RA(J2000)  = 14h 07m 58.17s
   Dec(J2000) = -50d 29' 06.3"
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This
location is 200 arcseconds from the BAT onboard position. 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 2.84
x 10^21 cm^-2 (Willingale et al. 2013). 

The initial flux in the 2.5 s image was 5.37e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 123 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. Because of the density of catalogued stars, further
analysis is required to report an upper limit for any afterglow in the
sub-image. The 8'x8' region for the list of sources generated on-board covers
100% of the XRT error circle. Because of the density of catalogued stars,
further analysis is required to report an upper limit for any afterglow in the
region. No correction has been made for the expected extinction corresponding
to E(B-V) of 0.26. 

Burst Advocate for this burst is F. E. Marshall (marshall 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: GRB171216A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22257
SUBJECT: GRB 171216A: Enhanced Swift-XRT position
DATE:    17/12/16 11:41:49 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 3440 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 171216A, 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 = 211.99069, -50.48474 which is equivalent
to:

RA (J2000): 14h 07m 57.77s
Dec (J2000): -50d 29' 05.1"

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) and Evans
et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB171205A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22258
SUBJECT: GRB 171205A: RATAN observations
DATE:    17/12/16 15:59:25 GMT
FROM:    Sergei Trushkin at Special Astrophys. Obs.,Russia  <sergei.trushkin@gmail.com>

S.A. Trushkin, A.K. Erkenov, P.G. Tsybulev and N.A. Nizhelskij (SAO RAS)
report:

We have observed GRB 171205A (D'Elia et al.; GCN Circ. 22177) with
the RATAN-600 radio telescope at 4.7 and 8.2 GHz from December 9 to
December 16 2017 daily. We have detected a radio fluxes within the RA
errors of the source detected with VLA (Laskar et al.; GCN Circ. 22216).
The mean flux densities are equal 15 +- 2 and 19 +- 2 mJy at 4.7 and 8.2
GHz respectively. But we must notice that there is a known NVSS source
J110939.0-123330  (32 mJy at 1.4 GHz), also detected in the
GLEAM multi-frequency survey: J110938-123334 in the field of GRB 171205A
(J110939.5-123518).
We have probably detected contributions from both sources with the
RATAN arcmin-beams. Thus if we subtract the fluxes from the
NVSS source, using the power-law fitting of its spectrum
we can estimate the refined fluxes from GRB 171205A:  < 3 mJy at 4.7 GHz
and 10 +- 3 mJy at 8.2 GHz for mean epoch: December 12 (MJD 58099.0),
i.e. ~7.3 days after the burst.

[GCN OPS NOTE(16dec17):  Per GCN, the extra, submitter-supplied 5-line
title-block was removed.]


GRB_name: GRB171216A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22259
SUBJECT: GRB 171216A: Swift-BAT refined analysis
DATE:    17/12/16 17:08:52 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+302 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 171216A (trigger #797441)
(Marshall et al., GCN Circ. 22256).  The BAT ground-calculated position is
RA, Dec = 212.013, -50.500 deg which is
  RA(J2000)  =  14h 08m 03.0s
  Dec(J2000) = -50d 30' 01.2"
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 63%.

The mask-weighted light curve shows a weak single-peaked structure that
starts at ~T0, peaks at ~T+3 s, and ends at ~ T+30 s. T90 (15-350 keV)
is 30.0 +- 7.5 sec (estimated error including systematics).

The time-averaged spectrum from T-0.45 to T+33.47 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.63 +- 0.30.  The fluence in the 15-150 keV band is 4.8 +- 1.0 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+3.05 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/797441/BA/


GRB_name: GRB171216A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22260
SUBJECT: GRB 171216A: Swift-XRT refined Analysis
DATE:    17/12/16 23:12:15 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A.
D'Ai (INAF-IASFPA), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU),
D.N. Burrows (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U.
Leicester) and F.E. Marshall report on behalf of the Swift-XRT team:

We have analysed 8.0 ks of XRT data for GRB 171216A (Marshall et al.
GCN Circ. 22256), from 134 s to 64.4 ks after the  BAT trigger. The
data are entirely in Photon Counting (PC) mode. The enhanced XRT
position for this burst was given by Goad et al. (GCN Circ. 22257).

The light curve can be modelled with an initial power-law decay with an
index of alpha=2.9 (+0.6, -0.3), followed by a break at T+456 s to an
alpha of 0.86 (+0.10, -0.09).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.76 (+0.16, -0.09). The
best-fitting absorption column is  consistent with the Galactic value
of 2.8 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum  is 4.2 x 10^-11 (5.3 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.8 (+/-0.3) x 10^21 cm^-2
Galactic foreground: 2.8 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.76 (+0.16, -0.09)

If the light curve continues to decay with a power-law decay index of
0.86, the count rate at T+24 hours will be 4.0 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.7 x
10^-13 (2.1 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00797441.

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


GRB_name: GRB171210A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22261
SUBJECT: GRB 171210A: Further Swift-XRT observations
DATE:    17/12/18 23:58:25 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. Dâ€™Avanzo, A. Melandri (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf of the Swift team: 
Swift-XRT has performed a second epoch of observations of the Fermi/LAT-detected burst GRB 171210A (Bissaldi et al. GCN Circ. 22228), collecting 4.4 ks of Photon Counting (PC) mode data between T0+563.0 ks and T0+662.2 ks. None of the five XRT-detected sources reported in Burrows at al. (GCN Circ. 22235) show any sign of significant fading between the two epochs of observation. We conclude that we have not detected the GRB afterglow. 
This circular is an official product of the Swift-XRT team.


GRB_name: GRB171216A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22262
SUBJECT: GRB 171216A: Swift/UVOT Upper Limits
DATE:    17/12/19 14:12:09 GMT
FROM:    Frank Marshall at Swift/UVOT  <marshall@milkyway.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 171216A
124 s after the BAT trigger (Marshall et al., GCN Circ. 22256).
No optical afterglow consistent with the XRT position
(Goad et al., GCN Circ. 22257)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           124          274          147         >21.3
u_FC               282          532          246         >18.4
v                  613        17562          371         >17.8
b                  539         6997          359         >19.8
u                  282         6886          678         >18.6
w1                 662         6681          452         >19.3
m2                 637         6476          274         >19.3
w2                 588        12734          720         >20.1

These preliminary results may be affected by the presence of
a bright source about 10" from the XRT position.

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.26 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB171216B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22263
SUBJECT: IPN Triangulation of GRB 171216B
DATE:    17/12/20 05:26:15 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova,
and T. Cline on behalf of the Konus-Wind team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

The long-duration GRB 171216B was detected
by Konus-Wind, INTEGRAL (SPI-ACS), CALET (CGBM), and
Mars-Odyssey (HEND) at about 51947 s UT (14:25:47).

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   340.068 (22h 40m 16s) +52.048 (+52d 02' 54")
  Corners:
   340.072 (22h 40m 17s) +51.848 (+51d 50' 54")
   339.877 (22h 39m 30s) +51.992 (+51d 59' 32")
   340.064 (22h 40m 15s) +52.248 (+52d 14' 54")
   340.259 (22h 41m 02s) +52.104 (+52d 06' 15")
  ---------------------------------------------
The error box area is 170 sq. arcmin, and its maximum
dimension is 24 arcmin (the minimum one is 10.0 arcmin).
The Sun distance was 100 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB171216_T51948/IPN

The time history and spectrum will be given in forthcoming GCN 
Circulars.


GRB_name: GRB171205A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22264
SUBJECT: GMRT Radio detection of GRB 171205A
DATE:    17/12/21 20:42:00 GMT
FROM:    Poonam Chandra at TIFR  <poonam@ncra.tifr.res.in>

Poonam Chandra (NCRA-TIFR, Stockholm University), A. J. Nayana
(NCRA-TIFR), Dipankar Bhattacharya (IUCAA), S. Bradley Cenko (NASA) and
Alessandra Corsi (Texas Tech University) report:

In our continuing follow up, we observed GRB 171205A (D'Elia et al., GCN 
Circ. 22177) with the Giant Metrewave Radio Telescope (GMRT) on 2017 Dec 
19.07 UT at 1400 MHz band. We detect radio emission at the GRB position 
(Laskar et al.  GCN 22216) with a flux density o 782+/-57 uJy. The map rms 
is 33 uJy.

More observations are planned. We thank the GMRT staff to schedule the
observations.


GRB_name: GRB171222A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22265
SUBJECT: GRB 171222A: Swift detection of a burst
DATE:    17/12/22 16:42:04 GMT
FROM:    Judith Racusin at GSFC  <judith.racusin@nasa.gov>

J. L. Racusin (NASA/GSFC), A. Deich (PSU), S. W. K Emery (UCL-MSSL),
J.D. Gropp (PSU), J. A. Kennea (PSU), H. A. Krimm (NSF/USRA),
N. P. M. Kuin (UCL-MSSL), A. Y. Lien (GSFC/UMBC),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
B. Sbarufatti (PSU) and A. Tohuvavohu (PSU) report on behalf of the
Swift Team:

At 16:24:59 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 171222A (trigger=799669).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 148.293, +35.622 which is 
   RA(J2000) = 09h 53m 10s
   Dec(J2000) = +35d 37' 18"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  As is usual with an image trigger, the BAT light 
curve does not show any significant features. 

The XRT began observing the field at 16:27:49.5 UT, 169.7 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 148.27784, 35.62759 which
is equivalent to:
   RA(J2000)  = 09h 53m 06.68s
   Dec(J2000) = +35d 37' 39.3"
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.  We
cannot determine whether the source is fading at the present time. No
spectrum from the promptly downlinked event data is yet available to
determine the column density. 

The initial flux in the 2.5 s image was 6.69e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 250 seconds with the U filter starting
175 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 19.2 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 18.0 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.01. 

Burst Advocate for this burst is J. L. Racusin (judith.racusin 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: GRB171222A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22266
SUBJECT: GRB 171222A: Enhanced Swift-XRT position
DATE:    17/12/22 21:08:18 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 689 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 171222A, 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 = 148.27736, +35.62712 which is equivalent
to:

RA (J2000): 09h 53m 6.57s
Dec (J2000): +35d 37' 37.6"

with an uncertainty of 3.0 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) and Evans
et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB171210A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22267
SUBJECT: GRB 171210A CALET Gamma-Ray Burst Monitor detection
DATE:    17/12/23 00:34:09 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

S. Matsukawa, A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo, M. Moriyama,
Y. Yamada, A. Tezuka (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 171210A (Bissaldi et al., GCN circ. 22228; Poolakkil et al.,
GCN circ. 22233; Kozlova et al., GCN circ. 22244) triggered the CALET Gamma-ray
Burst Monitor (CGBM) at 11:49:17.22 on 10 December 2017.  The burst signal was seen
by all the instruments.  Because of a problem in one of the ground alert processing
scripts, the GCN notice was not distributed automatically for this event.

The light curve of the SGM shows a single FRED-like pulse. The emission starts
at T-5 sec, peaks at T+5 sec and ends at T+50 sec.  The T90 duration measured
by the SGM data is 47.4 +- 2.5 sec (40-1000 keV).

The emission is seen up to ~T+180 s in the low energy ranges of the HXM data.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1196941607/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB171216B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22268
SUBJECT: GRB 171216B CALET Gamma-Ray Burst Monitor detection
DATE:    17/12/23 00:36:54 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

V. Pal'shin, A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama,
Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U),
S. Nakahira (RIKEN), I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The bright GRB 171216B (INTEGRAL SPI-ACS trigger #7972; Hurley et al.
GCN circ. 22263) triggered the CALET Gamma-ray Burst Monitor (CGBM) at
14:25:47.14 on 16 December 2017.  The burst signal was seen by the all instruments.

The light curve of the SGM shows several short peaks. The emission starts
at T0, peaks at T+3 sec and ends at T+5 sec.  The T90 duration measured
by the SGM data is 3.5 +- 0.4 sec (40-1000 keV).

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1197469387/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB171222A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22269
SUBJECT: GRB 171222A: NOT Optical Afterglow
DATE:    17/12/23 01:06:51 GMT
FROM:    Daniel Perley at Liverpool JMU  <d.a.perley@ljmu.ac.uk>

D. A. Perley (LJMU), D. Malesani (DARK/NBI), K. Heintz (Univ. Iceland,
DARK/NBI), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), and J. J. Lehiten
(MPS) report on behalf of a larger collaboration:

We obtained observations of GRB 171222A (Racusin et al., GCN 22265)
using StanCam on the Nordic Optical Telescope, beginning at 00:08:31 UT
on 2017-12-23.  Imaging was obtained in both R and I bands.

In the raw images we identify an optical source, not visible in
pre-imaging from Pan-STARRS, at the following location within the XRT
error circle (Osborne et al. GCN 22266):

RA = 09:53:06.73
Dec = +35:37:35.5

We suggest that this source is the optical afterglow of GRB 171222A.
Provisional photometry relative to nearby USNO stars gives a magnitude
of R = 21.44 +/- 0.09 (at 7.67 hours after the GRB trigger).


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22270
SUBJECT: GRB 171205A: SMARTS optical/IR supernova monitoring
DATE:    17/12/23 04:25:55 GMT
FROM:    Bethany Cobb at GWU  <bcobb@gwu.edu>

B. E. Cobb (GWU), reports:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained additional optical/IR imaging of the error region of
GRB 171205A (GCN 22177, D'Elia et al.). At each epoch,
total summed exposure times amounted to 15 min in V and I
and 12 min in J and K.

Between approximately 1 and 2 days post-burst, the optical/IR
afterglow of GRB 171205A (GCN 22180, Izzo et al.;
GCN 22181, Emery et al.; GCN 22182, Butler et al.;
GCN 22186, Mao et al.; GCN 22188, Choi et al.;
GCN 22189, Melandri et al.; GCN 22190, Steeghs et al.;
GCN 22192, Cobb; GCN 22193, Volnova et al.;
GCN 22195, Mao et al.; GCN 22197, Guidorzi et al.;
GCN 22198, Schmidl & Schady; GCN 22199, Lipunov et al.;
GCN 22202, Siegel et al.; GCN 22205, Volnova et al.;
GCN 22215, Laskar et al.; GCN 22223, Volnova et al.;
GCN 22224, Volnova et al.; GCN 22225, Hentunen & Nissinen;
GCN 22226, Lipunov et al.) is clearly seen to dim. After about 6 days
post-burst, however, a brightening is detected. This brightening is
due to the emergence of the underlying supernova associated with
GRB 171205A, and is consistent with the spectroscopic
detection of this supernova by de Ugarte Postigo et al. (GCN 22204).

Approximate I-band and J-band magnitudes are given below.

days
post-burst      I mag   J mag
1.02056         17.7    17.6
2.03260         18.1    17.9
4.03747         18.2    18.0
6.01435         18.1    17.6
10.98015        17.7    17.5
17.01212        17.6    17.0

(Optical photometry is calibrated against Landolt standard stars;
and IR photometry is calibrated against 2MASS stars in the
field. The magnitudes include afterglow and host galaxy contributions
and should be considered only highly preliminary values.)


GRB_name: GRB171222A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22271
SUBJECT: GRB 171222A: Swift-XRT refined Analysis
DATE:    17/12/23 05:49:30 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), B.
Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), A. Tohuvavohu (PSU),
S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester) and J.L. Racusin report on behalf of the Swift-XRT team:

We have analysed 8.1 ks of XRT data for GRB 171222A (Racusin et al. GCN
Circ. 22265), from 176 s to 39.8 ks after the  BAT trigger. The data
comprise 386 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Osborne et al. (GCN Circ. 22266).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=2.05 (+0.39, -0.25). At T+285 s  the decay
steepens to an alpha of 4.51 (+0.43, -0.18). The light curve breaks
again at T+533 s to a decay with alpha=7.78 (+0.22, -1.07),  and  again
at T+712 s s to alpha=2.9 (+/-0.6),  before a final break at T+2103 s s
after which the decay index is 0.09 (+0.24, -0.27).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.28 (+/-0.04). The
best-fitting absorption column is  6.2 (+/-0.8) x 10^20 cm^-2, in
excess of the Galactic value of 1.1 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.99 (+0.15, -0.12)
and a best-fitting absorption column consistent with the Galactic
value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.2 x 10^-11 (3.3 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.1 (+2.4, -0.0) x 10^20 cm^-2
Galactic foreground: 1.1 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.99 (+0.15, -0.12)

If the light curve continues to decay with a power-law decay index of
0.09, the count rate at T+24 hours will be 0.021 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 6.7 x
10^-13 (7.0 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00799669.

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


GRB_name: GRB171222A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22272
SUBJECT: GRB 171222A: Redshift from 10.4m GTC/OSIRIS
DATE:    17/12/23 07:06:51 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), L. Izzo (HETH/IAA-CSIC), 
D.A. Kann (HETH/IAA-CSIC), C.C. Thoene (HETH/IAA-CSIC), D. A. Perley 
(LJMU), D. Malesani (DARK/NBI), K.E. Heintz (Univ. Iceland, DARK/NBI), 
D. Garcia (GTC) report on behalf of a larger collaboration,

We observed the afterglow of GRB 171222A (Racusin et al. GCN 22265; 
Osborne et al. GCN 22266; Perley et al. GCN 22269) using the 10.4m GTC 
telescope equipped with OSIRIS. Observations consisted of 3x900s exposures 
using grism R1000B, covering the range from 3700 to 7880 AA. The mean time 
of the combined spectrum is 3:11 UT (10.77 hr after the burst).

The combined spectrum shows a power-law continuum over the complete 
spectral range with several weak absorption features. We identify the strongest 
of them as Ly-alpha at a redshift of 2.409, with marginal detections of SiII, SiIV 
and CIV at the same redshift, which we identify as the redshift of the GRB. 
An intervening system at z=1.678 is also identified through the detection of MgII 
absorption.


GRB_name: GRB171222A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22273
SUBJECT: GRB 171222A: MASTER-Net OT observations
DATE:    17/12/23 11:26:55 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

N.Tyurina, V. Lipunov, E. Gorbovskoy,V.Kornilov, D.Kuvshinov, A.V.Krylov, 
I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko
Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU

R.Podesta, C.Lopez, F. Podesta Observatorio Astronomico Felix Aguilar (OAFA),
National University of San Juan, Argentina

H. Levato, C. Saffe
Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE),
San Juan, Argentina

D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias

O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk,
Irkutsk State University

V.Yurkov, Yu.Sergienko
Blagoveschensk Educational State University, Blagoveschensk

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory


MASTER-IAC  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in IAC (Tenerife) was pointed to the Swift  GRB171222A (Racusin et 
al.,  GCN  #22265;) 47159 seconds (~ 13h ) 
after trigger time at 2017-12-23  05:31:03 UT.
The 5-sigma upper limit has been about 19.3  at single (180 s) and 20.9 at 
coadd (10x180 = 1800 s ) images.

We see OT detected by (Perley et al., GCN #22269; de Ugarte Postigo et 
al., GCN #22272 ) at X-ray position (Osborne et al.,  GCN #22266; D'Elia 
et al., GCN #22271).

The OT unfiltered magnitude is about ~ 21.

The observations made on zenit distance = 11 degrees, galaxy latitude b = 
52 degree.
The moon (21 % bright part) below the horizon (The altitude of the Moon is 
-73 degree ).
The sun  altitude  is -30.5 degree.
The object can be observed till sunrise at 2017-12-23 07:54:43 .

This message can be cited.


GRB_name: GRB171222A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22274
SUBJECT: GRB 171222A: Nanshan-1m optical afterglow detection
DATE:    17/12/23 14:00:59 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

X. Zhang, P. Zong, J.H. Liu (XAO), H.X. Feng, Z.P. Zhu, D. Xu (NAOC), 
H.B. Niu, J.Z. Liu, A. Esamdin, L. Ma, Y. Zhang (XAO) report on behalf 
of a larger collaboration:

We observed the field of GRB 171222A (Racusin et al., GCN 22265) using 
the 1m telescope located at Nanshan, Xinjiang, China. We obtained 6x300s 
R-band frames, starting at 18:14:36 UT on 2017-12-22, i.e., 1.83 hr 
after the BAT trigger.

An uncatalogued and fading optical transient (OT) is detected at the XRT 
position (Osborne et al., GCN 22266) as well as the NOT position (Perley 
et al., GCN 22269) in our images. Preliminary photometry results are as 
follows:

Tmid-T0 Exposure  Filter    Mag(R)    MagErr(R)
(hr)           (s)
1.87        1x300       R        20.86        0.21
2.68        3x300       R        21.47        0.22
7.87        2x300       R        21.72        0.22

Photometry is calibrated with nearby USNO-B1.0 stars (R2 magnitudes), 
and errors are only statistical values. We thus conclude that this OT is 
the optical afterglow of GRB 171222A.


GRB_name: GRB171222A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22275
SUBJECT: GRB 171222A: Swift/UVOT Upper Limits
DATE:    17/12/23 14:09:12 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and J. L. Racusin (NASA/GSFC) report on
behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 171222A
176 s after the BAT trigger (Racusin et al., GCN Circ. 22265). No
optical afterglow consistent with the enhanced XRT position (Osborne
et al. GCN Circ 22266) or the NOT position (Perley et al., GCN Circ
22269) is detected in the initial UVOT exposures.
The optical afterglow was detected however by Perley et al. (GCN Circ
22269), Tyurina et al. (GCN Circ. 22273), and a redshift was reported
by de Ugarte Postigo (GCN Circ. 22272).
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding
chart (FC) exposure and subsequent exposures are:

 Filter T_start(s) T_stop(s) Exp(s) Mag

 u_FC     176         426      246   >20.6
 u        176        1026      393   >20.3
 b        432        1795      175   >20.3
 v        482        1846      175   >19.2
 uvw1     531        1895      175   >19.4
 uvm2     506        1870      175   >19.3
 uvw2     458        1821      175   >19.6

The magnitudes in the table are not corrected for the Galactic
extinction due to the reddening of E(B-V) = 0.01 in the direction
of the burst (Schlegel et al. 1998).


GRB_name: GRB171222A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22276
SUBJECT: GRB 171222A: Nanshan-0.36m optical upper limit
DATE:    17/12/23 14:34:17 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

H.J. Tan (CCU), H.X. Feng, Z.P. Zhu, D. Xu (NAOC), X. Gao (Urumqi No.1 
Senior High School) report

We observed the field of GRB 171222A (Racusin et al., GCN 22265) using 
the 0.36m robotic telescope located at Nanshan, Xinjiang, China. 
Observations started at 17:04:17 UT on 2017-12-22, i.e., 39.3 mins after 
the BAT trigger, and all imaged were taken without filter.

No optical source is detected at the XRT position (Osborne et al., GCN 
22266) as well as the NOT position (Perley et al., GCN 22269), down to a 
limiting magnitude of m(R)~19.3, calibrated with the USNO B1 field.


GRB_name: GRB171222A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22277
SUBJECT: GRB 171222A: Fermi GBM detection
DATE:    17/12/23 17:13:20 GMT
FROM:    Matthew Stanbro at UAH/Fermi  <mcs0001@uah.edu>

M. Stanbro (UAH), C. M. Hui (NASA/MSFC) and C. Meegan (UAH)
reports on behalf of the Fermi GBM Team:

At 16:25:10.54 UT on 22 December 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171222A (trigger 535652715/171222684) which
was also detected by the Swift/BAT and XRT (Racusin et al. 2017, GCN 22265).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 43 degrees.

The GBM light curve shows a single peak with a duration (T90)
of about 80.4s (50-300 keV).  The time-averaged spectrum from
T0+0.0s to T0+78.8s is adequately fit by a power law function with
an exponential high-energy cutoff.  The power law index is
-1.09+/- 0.27 and the cutoff energy, parameterized as Epeak,
is 29.18 +/- 2.73 keV.

The event fluence (10-1000 keV) in this time interval is
(2.27 +/- 0.13)E-06 erg/cm^2. The 1s peak photon flux measured
starting from T0+60.1s in the 10-1000 keV band is 2.3 +/- 0.2 ph/s/cm^2.

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


GRB_name: GRB171223A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22278
SUBJECT: GRB 171223A: Fermi GBM detection
DATE:    17/12/24 05:11:48 GMT
FROM:    Matthew Stanbro at UAH/Fermi  <mcs0001@uah.edu>

M. Stanbro and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 19:38:15.07 UT on 23 December 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171223A (trigger 535750700 / 171223818).

The on-ground calculated location, using the GBM trigger
data, is RA = 115.84, DEC = -33.48, with an uncertainty
of 6.59 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg
systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ).

The trigger resulted in an Autonomous Repoint Request (ARR)
by the GBM Flight Software owing to the high peak flux
of the GRB. This ARR was accepted and the spacecraft slewed to the GBM
in-flight
location. The initial angle from the Fermi LAT boresight to
the best location is 56 degrees.

The GBM light curve consists of 1 pulse
with a duration (T90) of about 0.38 s (50-300 keV).
The time-averaged spectrum from T0-0.13 s to T0+0.32 s is
best fit by a Band function with Epeak = 1156 +/- 193 keV,
alpha = -0.67 +/- 0.07, and beta = -2.42 +/- 0.28.

The event fluence (10-1000 keV) in this time interval is
(1.98 +/- 0.06)E-06 erg/cm^2. The 64-millisec peak photon flux measured
starting from T0+0.064 s in the 10-1000 keV band
is 23.8 +/- 1.2 ph/s/cm^2.

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


GRB_name: GRB171222A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22279
SUBJECT: GRB 171222A: AROMA-N optical observation
DATE:    17/12/24 10:01:22 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

Y. Kitaoka, T. Sakamoto (AGU)

We observed the field of GRB 171222A detected by Swift (Racusin et al.
GCN circ. 22265) with the 0.3 m AROMA-N telescope located at
Aoyama Gakuin University (Sagamihara, Japan).  Due to the introduction
issue of the telescope, we only obtained one 120 sec image which contains
the location of the GRB.  The image was taken in the R filter starting from
December 12 on 18:53:26 (UT) about 140 minutes after the trigger and stopped
on 18:55:26 (UT).  We do not detect the optical afterglow in this image at
the location of the X-ray afterglow (Osborne et al. GCN circ. 22266).
The estimated five sigma upper limit is ~15.3 using the USNO-B1 catalog.


GRB_name: GRB171222A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22280
SUBJECT: GRB 171222A: Swift-BAT refined analysis
DATE:    17/12/24 12:41:04 GMT
FROM:    Hans Krimm at NASA-GSFC/NSF  <hans.krimm@nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC),  J. R. Cummings (CPI),
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
J. L. Racusin (NASA/GSFC),  T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (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 171222A (trigger #799669)
(Racusin, et al., GCN Circ. 22265).  The BAT ground-calculated position is
RA, Dec = 148.273, 35.624 deg which is
    RA(J2000)  =  09h 53m 05.4s
    Dec(J2000) = +35d 37' 24.9"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 60%.

The mask-weighted light curve shows multiple overlapping peaks in three 
groupings.
The first runs from approximately T-10 sec to T+50 sec, the second from 
T+50 sec
to T+90 sec, and the third, weakest group from T+90 sec to T+200 sec.
T90 (15-350 keV) is 174.8 +- 22.7 sec (estimated error including 
systematics).

The time-averaged spectrum from T+8.00 to T+209.82 sec is best fit by a 
simple
power-law model.  The power law index of the time-averaged spectrum is
2.07 +- 0.17.  The fluence in the 15-150 keV band is 1.9 +- 0.2 x 10^-6 
erg/cm2.
The 1-sec peak photon flux measured from T+61.34 sec in the 15-150 keV band
is 0.7 +- 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/799669/BA/


GRB_name: GRB171216B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22284
SUBJECT: Konus-Wind observation of GRB 171216B
DATE:    17/12/25 15:37:42 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, A. Tsvetkova, A. Lysenko, A.Kozlova, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration, hard-spectrum GRB 171216B
(IPN triangulation: Hurley et al., GCN circ. 22263;
CALET-CGBM detection: Pal'shin et al., GCN circ. 22268)
triggered Konus-Wind at T0=51948.499 s UT (14:25:48.499).

The burst light curve shows a multipeaked structure
which starts at ~T0-0.3 s and has a total duration of ~7.4 s.
The emission is seen up to ~5 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB171216_T51948/

As observed by Konus-Wind, the burst
had a fluence of 1.59(-0.29,+0.37)x10^-5 erg/cm2,
and a 16-ms peak flux, measured from T0+0.034 s,
of 2.32(-1.00,+1.15)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 10 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -1.11(-0.11,+0.13)
and Ep = 1341(-412,+673) keV (chi2 = 85/98 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.3
(chi2 = 85/97 dof).

The spectrum near the maximum count rate
(measured from T0 to T0+0.064 s)
is best fit in the 20 keV - 10 MeV range
by a power law with exponential cutoff model:
with  alpha = -0.34(-0.37,+0.52)
and Ep = 994(-372,+539) keV (chi2 = 15/16 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.2
(chi2 = 15/15 dof).

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


GRB_name: GRB171212C
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22285
SUBJECT: GRB 171212C CALET Gamma-Ray Burst Monitor detection
DATE:    17/12/26 02:21:16 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

K. Yamaoka (Nagoya U), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), S. Nakahira (RIKEN),
I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 171212C (Konus-Wind trigger time on 22:53:41.759)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 22:53:37.68 on
12 December 2017.  The burst signal was seen only by the SGM instrument.

The light curve of the SGM shows two weak pulses.  The emission starts
at T0, peaks at T+0.5 sec and ends at T+30 sec.  The T90 duration measured
by the SGM data is 27.2 +- 3.6 sec (40-1000 keV).  The T50 duration measured
by the SGM data is 18.1 +- 4.5 sec (40-1000 keV).

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1197154263/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.

[GCN OPS NOTE(11jan18): Per author's request, the name of the GRB was changed
from 171212A to 171212C.]


GRB_name: GRB171223A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22286
SUBJECT: GRB 171223A: Insight-HXMT/HE detection
DATE:    17/12/26 07:36:17 GMT
FROM:    Xufang Li at IHEP  <lixufang@ihep.ac.cn>

X.F. Li, S. L. Xiong, X. B. Li, C. K. Li, C. Z. Liu,

Z. W. Li, Z. Chang, X. F. Lu, J. L. Zhao, A. M. Zhang, Y. F. Zhang,
C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU),
F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:



At 2017-12-23T19:38:15.000 (T0), Insight-HXMT/HE detected GRB 171223A 

(trigger ID: HEB171223818) in a routine search of the data, which was

also observed by Fermi/GBM(M. stanbro and C. Meegan, GCN Circ.22278)


The Insight-HXMT light curve mainly consists of multiple pulses
with a duration (T90) of 0.17 s measured from T0+0.0735 s.
The 0.01s peak rate, measured from T0+0.109 s, is 38390.0 cnts/sec.
The total counts from this burst is 3198 counts.

URL_LC: http://www.hxmt.org/images/GRB/HEB171223818_lc.jpg

All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.

The analysis results presented above are preliminary;
final results will be published elsewhere.

Insight-HXMT is the first Chinese space X-ray telescope, which was funded
jointly by the China National Space Administration (CNSA) and the Chinese
Academy of Sciences (CAS). More information about it could be found at:
http://www.hxmt.org/index.php/enhome .


GRB_name: GRB171215A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22287
SUBJECT: GRB 171215A: Insight-HXMT/HE detection
DATE:    17/12/26 14:45:17 GMT
FROM:    Qiang Zhang at IHEP  <zhangqiang@ihep.ac.cn>

Q. Zhang, S. L. Xiong, X. B. Li, C. K. Li, J. Y. Liao, C. Z. Liu,
X. F. Li, Z. W. Li, X. F. Lu, Z. Chang, J. L. Zhao, A. M. Zhang,
C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU),
F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:

At 2017-12-15T16:55:22 (T0), Insight-HXMT/HE detected GRB 171215A 
(trigger ID: HEB171215705) in a routine search of the data,which is also 
detected by Fermi/GBM and CALET.

The Insight-HXMT light curve consists of multi-pulses
with T90 of  32.2s measured from T0+0.84 s.
The 500-ms peak rate, measured from T0+5.0 s, is 2147.7 cnts/sec.
The total counts from this burst is 14798.6 counts.

URL_LC: http://www.hxmt.org/images/GRB/HEB171215705_lc.jpg

All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.

The analysis results presented above are preliminary;
final results will be published elsewhere.

Insight-HXMT is the first Chinese space X-ray telescope, which was funded
jointly by the China National Space Administration (CNSA) and the Chinese
Academy of Sciences (CAS). More information could be found at:
http://www.hxmt.org/index.php/enhome .


GRB_name: GRB171227A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22288
SUBJECT: GRB 171227A: AGILE/MCAL detection
DATE:    17/12/27 18:34:44 GMT
FROM:    Francesco Verrecchia at ASDC  <francesco.verrecchia@ssdc.asi.it>

F. Verrecchia (SSDC and INAF/OAR), A.Ursi (INAF/IAPS), A. Trois
(INAF/OA-Cagliari), C. Pittori (SSDC and INAF/OAR), M. Tavani (INAF/IAPS, and
Univ. Roma Tor Vergata), M. Marisaldi (INAF/IASF-Bo and Bergen University),
N. Parmiggiani (INAF/IASF-Bo), F. Longo (Univ. Trieste and INFN Trieste),
A. Bulgarelli (INAF/IASF-Bo), M. Cardillo, M. Pilia (INAF/OA-Cagliari), G.
Piano (INAF/IAPS), I. Donnarumma (ASI), G. Minervini, A. Argan, Y. Evangelista
(INAF/IAPS), F. Lucarelli (SSDC and INAF/OAR),  V. Fioretti, F. Fuschino
(INAF/IASF-Bo),  A. Giuliani (INAF/IASF-Mi), report on behalf of the AGILE
Team:

The AGILE Mini-CALorimeter (MCAL) detected a long burst at
T0 = 2017-12-27 00:00:30.00 +/- 0.01 UTC in the acquired data interval (following
an internal trigger) started at T1=00:00:29.00 UTC
and ended at 00:00:46.50 UTC.
The MCAL light curve shows a multi-peaked structure, with the main part within
T0+0.70 s and T0+5.50 s and a second short peak at T0+10.50 s. The main GRB interval
released a total number of ~28190 counts at E>400 keV in the detector,
above an average background rate of 23 counts/32ms.

The AGILE-MCAL detector has a full solid angle acceptance, and is operational
in the range 0.4 - 100 MeV.


GRB_name: GRB171227A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22289
SUBJECT: GRB 171227A: Fermi GBM detection
DATE:    17/12/27 18:55:27 GMT
FROM:    C. Michelle Hui at MSFC/Fermi-GBM  <c.m.hui@nasa.gov>

C. M. Hui (NASA/MSFC)
reports on behalf of the Fermi GBM Team:

At 00:00:13.40 UT on 27 December 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 171227A (trigger 536025618/171227000),
also detected by AGILE/MCAL (Verrecchia et al. GCN 22288).

The on-ground calculated location, using the GBM trigger data,
is RA = 280.7 , DEC = -35.0  (J2000 degrees,
equivalent to 18h 42m, -35d 0.0'), with an uncertainty of 1.0 degrees 
(radius, 1-sigma containment, statistical only; 
there is additionally a systematic error which we have characterized 
as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error 
and a small tail with a systematic error of more than 10 deg 
[Connaughton et al. 2015, ApJS, 216, 32] ).
The angle from the Fermi LAT boresight is 120 degrees.

The GBM light curve shows several peaks with decreasing amplitudes
and a duration (T90) of about 38 s (50-300 keV). 
The time-averaged spectrum from T0+0.0 s to T0+58.2 s is 
adequately fit by a Band function with Epeak = 771 +/- 14 keV, 
alpha = -0.87 +/- 0.01, and beta = -2.47 +/- 0.04.

The event fluence (10-1000 keV) in this time interval is 
(305.3 +/- 1.3) E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+19.4 s in the 10-1000 keV band is 90.3 +/- 0.7 ph/s/cm^2.

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


GRB_name: GRB171227A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22290
SUBJECT: IPN Triangulation of GRB 171227A
DATE:    17/12/28 15:01:10 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and

G. Di Cocco, F. Fuschino, M. Galli, C. Labanti, M. Marisaldi,
and A. Ursi on behalf of the AGILE MCAL team, report:

The long-duration GRB 171227A
(AGILE-MCAL detection: Verrecchia et al.,
GCN Circ. 22288, Fermi-GBM observation: Hui et al., GCN Circ. 22289)
was detected by Konus-Wind, Fermi (GBM trigger 536025618), INTEGRAL 
(SPI-ACS),
and AGILE (MCAL) at about 13 s UT (00:00:13).

We have triangulated it to a preliminary, 3-sigma error box whose 
coordinates are:
---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   290.998 (19h 24m 00s) -47.012 (-47d 00' 43")
  Corners:
   295.738 (19h 42m 57s) -48.264 (-48d 15' 50")
   284.827 (18h 59m 19s) -46.296 (-46d 17' 44")
   287.178 (19h 08m 43s) -45.288 (-45d 17' 16")
   298.814 (19h 55m 15s) -46.606 (-46d 36' 22")
  ---------------------------------------------
The error box area is 12.8 sq. deg, and its maximum
dimension is 9.6 deg (the minimum one is 96.7 arcmin).
The Sun distance was 24 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB171227_T00009/IPN

The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.


GRB_name: GRB171227A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22291
SUBJECT: Konus-Wind observation of GRB 171227A
DATE:    17/12/29 13:52:39 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova@mail.ioffe.ru>

A. Tsvetkova, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Lysenko, A.Kozlova, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration, hard-spectrum, very intense GRB 171227A
(AGILE/MCAL detection: Verrecchia et al., GCN 22288;
Fermi GBM detection: Hui, GCN 22289;
IPN Triangulation: Kozlova et al., GCN 22290)
triggered Konus-Wind at T0=9.491 s UT (00:00:09.491).
The burst light curve shows a multi-peaked structure
with a total duration of ~56 s.
The emission is seen up to ~19 MeV.

As observed by Konus-Wind, the burst
had a fluence of 6.31(-0.19,+0.19)x10^-4 erg/cm2,
and a 64-ms peak flux, measured from T0+18.880 s,
of 1.19(-0.10,+0.10)x10^-4 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+60.416 s)
is best fit in the 20 keV - 19 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.87(-0.03,+0.03),
the high energy photon index beta = -2.12(-0.06,+0.05),
the peak energy Ep = 618(-35,+38) keV
(chi2 = 139/97 dof)

The spectrum near the maximum count rate
(measured from T0+18.176 to T0+18.944 s)
is best fit in the 50 keV - 19 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.77(-0.07,+0.08),
the high energy photon index beta = -2.38(-0.26,+0.16),
the peak energy Ep = 1498(-215,+262) keV
(chi2 = 62/73 dof)

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB171227_T00009/

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


GRB_name: GRB180102A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22292
SUBJECT: GRB 180102A: Swift detection of a burst
DATE:    18/01/02 16:01:33 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

K. L. Page (U Leicester), A. A. Breeveld (UCL-MSSL),
D. N. Burrows (PSU), A. Deich (PSU), C. Gronwall (PSU),
J.D. Gropp (PSU), J. A. Kennea (PSU), H. A. Krimm (NSF/USRA),
N. P. M. Kuin (UCL-MSSL), A. Y. Lien (GSFC/UMBC),
A. Melandri (INAF-OAB), D. M. Palmer (LANL), M. H. Siegel (PSU) and
A. Tohuvavohu (PSU) report on behalf of the Swift Team:

At 15:49:44 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180102A (trigger=802999).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 203.115, +62.148 which is 
   RA(J2000) = 13h 32m 28s
   Dec(J2000) = +62d 08' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 40 sec.  The peak count rate
was ~1800 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 15:50:54.4 UT, 70.2 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 203.06761, 62.17091 which is equivalent
to:
   RA(J2000)  = 13h 32m 16.23s
   Dec(J2000) = +62d 10' 15.3"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 114 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.  We cannot determine whether the source is
fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 1.88
x 10^20 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 73 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 0.01. 

Burst Advocate for this burst is K. L. Page (klp5 AT leicester.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: GRB180102A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22293
SUBJECT: GRB 180102A: Prompt enhanced Swift-XRT position
DATE:    18/01/02 16:38:02 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using  promptly downlinked XRT event data for GRB 180102A, we find an
enhanced XRT position of the afterglow: RA, Dec: 203.0669, 62.1718
which is equivalent to:
   RA (J2000)  = 13 32 16.07
   Dec (J2000) = +62 10 18.6
with an uncertainty of 2.1 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at
http://www.swift.ac.uk/sper/802999.

Position enhancement is is described by Goad et al. (2007, A&A, 476,
1401) and Evans et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB180102A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22294
SUBJECT: GRB 180102A: Enhanced Swift-XRT position
DATE:    18/01/02 19:39:31 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 611 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 180102A, 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 = 203.06658, +62.17177 which is equivalent
to:

RA (J2000): 13h 32m 15.98s
Dec (J2000): +62d 10' 18.4"

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) and Evans
et al. (2009, MNRAS, 397, 1177).

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


GRB_name: GRB180102A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22295
SUBJECT: GRB 180102A: Fermi GBM detection
DATE:    18/01/02 20:38:51 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P. Veres (UAH) reports on behalf of the Fermi GBM Team:

"At 15:49:47.21 UT on 2 January 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180102A (trigger 536600992 / 180102660) which
was also detected by Swift/BAT (Page et al., GCN 22292).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 60 degrees.

The GBM light curve consists of a single pulse
with a duration (T90) of about 16 s (50-300 keV).
The time-averaged spectrum from T0-6.1 s to T0+2.0 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.40 +/- 0.44 and
the cutoff energy, parameterized as Epeak, is 54.9 +/- 6.7 keV.

The event fluence (10-1000 keV) in this time interval is
(4.31 +/- 0.45)E-7 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.7 s in the 10-1000 keV band
is 1.76 +/- 0.19 ph/s/cm^2.

A Band function fits the spectrum equally well with Epeak= 41.8 +/- 9.2 keV,
 alpha = 0.59 +/- 1.18 and beta = 2.52 +/- 0.35.

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


GRB_name: GRB180102A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22296
SUBJECT: GRB 180102A: Swift-XRT refined Analysis
DATE:    18/01/02 23:26:33 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), D.N. Burrows (PSU), A.
Tohuvavohu (PSU), S. J. LaPorte (PSU), J.P. Osborne (U. Leicester),
A.P. Beardmore (U. Leicester), P. D'Avanzo (INAF-OAB) and K.L. Page
report on behalf of the Swift-XRT team:

We have analysed 6.7 ks of XRT data for GRB 180102A (Page et al. GCN
Circ. 22292), from 82 s to 19.2 ks after the  BAT trigger. The data are
entirely in Photon Counting (PC) mode. The enhanced XRT position for
this burst was given by Beardmore et al. (GCN Circ. 22293).

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.55 (+/-0.06).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.31 (+0.32, -0.30). The
best-fitting absorption column is  4.0 (+1.4, -1.2) x 10^21 cm^-2, in
excess of the Galactic value of 1.9 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.3 x 10^-11 (6.3 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      4.0 (+1.4, -1.2) x 10^21 cm^-2
Galactic foreground: 1.9 x 10^20 cm^-2
Excess significance: 5.2 sigma
Photon index:      2.31 (+0.32, -0.30)

If the light curve continues to decay with a power-law decay index of
0.55, the count rate at T+24 hours will be 6.5 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.2 x
10^-13 (4.1 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00802999.

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


GRB_name: GRB180102A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22297
SUBJECT: GRB 180102A: MASTER-Net robotic report
DATE:    18/01/03 08:10:16 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, N.Tyurina,  V.Kornilov, D.Kuvshinov, 
A.V.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko
Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU

V.Yurkov, Yu.Sergienko
Blagoveschensk Educational State University, Blagoveschensk

R.Podesta, C.Lopez, F. Podesta Observatorio Astronomico Felix Aguilar (OAFA),
National University of San Juan, Argentina

H. Levato, C. Saffe
Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE),
San Juan, Argentina

D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias

O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk,
Irkutsk State University

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory


MASTER-Kislovodsk  robotic telescope (MASTER-Net: 
http://observ.pereplet.ru) 
located in Kislovodsk was pointed to the  GRB180102A 23 sec after notice 
time and 43 sec after trigger time at 2018-01-02 15:50:27 UT (Page et 
al., GCN #22292;  Veres GCN22295). On our first 
(10s exposure)  set we haven't found optical transient  within Swift 
error-box (D'Ai et al., GCN #22296; Beardmore et al., GCN 22294).
The 5-sigma upper limit has been about 13.7 mag
The message may be cited.


The observations made on zenit distance = 74 degrees, galaxy latitude b = 
55 degree.
The moon (99 % bright part) is 14 degrees above the horizon. The distance 
between  moon and  object is 73
The sun  altitude  is -22.3 degree.
The object can be observed till sunrise at 2018-01-03 04:41:55.

MASTER-Tavrida  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Crimea was pointed to the  GRB180102.66 3221 sec after notice 
time and 3247 sec after trigger time at 2018-01-02 16:43:51 UT. On our 
22-th (180s exposure)  set we haven't found optical transient  within 
SWIFT error-box (ra=203.113 dec=62.1472 r=0.05).
The message may be cited.


The observations made on zenit distance = 73 degrees, galaxy latitude b = 
55 degree.
The moon (99 % bright part) is 18 degrees above the horizon. The distance 
between  moon and  object is 73
The sun  altitude  is -25.8 degree.
The object can be observed till sunrise at 2018-01-03 05:20:03.

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Blagoveschensk was pointed to the  GRB180102.66 21451 sec after 
notice time and 21471 sec after trigger time at 2018-01-02 21:47:35 UT. We 
not optical transient within  SWIFT error-box (ra=203.113 dec=62.1472 
r=0.05) brighter then 16.7.

The 5-sigma upper limit has been about 16.24mag
The message may be cited.

The observations made on zenit distance = 12 degrees, galaxy latitude b = 
55 degree.
The moon (99 % bright part) is 20 degrees above the horizon. The distance 
between  moon and  object is 72
Observations started at twilight.
The sun  altitude  is -15.2 degree.
The object can be observed till sunrise at 2018-01-03 23:26:49

This message can be cited.


GRB_name: GRB180102A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22298
SUBJECT: GRB 180102A: NOT optical observations
DATE:    18/01/03 08:20:40 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani (DARK/NBI), K. E. Heintz (Univ. Iceland and DARK/NBI), A. 
Sagues Carracedo (NOT), Andreas Kjaer Dideriksen (Aarhus Univ.), report 
on behalf of a larger collaboration:

We observed the field of GRB 180102A (Page et al., GCN 22292; Veres, GCN 
22295) with the Nordic Optical Telescope (NOT) equipped with the AlFOSC 
camera. Observations were carried out in the SDSS r and z filters (900 
and 1000 s exposure, respectively), with a seeing of 1.5", and started 
on 2018 Jan 3.1769 UT (12.42 hr after the GRB trigger).

At the position of the X-ray counterpart (D'Ai et al., GCN 22296), no 
objects are detected down to (preliminary) limiting magnitudes r = 22.5, 
z = 22.0 (all AB, calibrated with reference to nearby Pan-STARRS stars).


GRB_name: GRB180102A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22299
SUBJECT: GRB 180102A: Swift/UVOT Upper Limits
DATE:    18/01/03 12:37:47 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180102A 74 
s after the BAT trigger (Page et al., GCN Circ. 22292).
No optical afterglow consistent with the XRT position (Beardmore et al. 
GCN Circ. 22294) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system 
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding 
chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            74          224          147         >20.8
u_FC               286          535          246         >19.9
white               74         7508          824         >21.3
v                  616         6484          352         >19.3
b                  541         7303          529         >20.3
u                  286         7098          717         >20.4
w1                 665         6893          529         >20.1
m2                 640         6688          350         >19.7
w2                 591         7692          528         >20.1

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.01 in the direction of the 
burst (Schlegel et al. 1998).


GRB_name: GRB180102A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22300
SUBJECT: GRB 180102A: Swift-BAT refined analysis
DATE:    18/01/03 16:06:40 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

T. Sakamoto (AGU), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-61 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180102A (trigger #802999)
(Page et al. GCN Circ. 22292).  The BAT ground-calculated position is
RA, Dec = 203.078, 62.161 deg which is
  RA(J2000)  =  13h 32m 18.8s
  Dec(J2000) = +62d 09' 38.1"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 95%.

The mask-weighted light curve shows two overlapping pulses that starts
at ~ T-8 s and ends at ~ T+6 s. The main peak occurs at ~T+1 s.
T90 (15-350 keV) is 10.8 +- 1.7 sec (estimated error including systematics).

The time-averaged spectrum from T-7.62 to T+6.30 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.01 +- 0.18.  The fluence in the 15-150 keV band is 3.5 +- 0.4 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.80 sec in the 15-150 keV band
is 1.0 +- 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/802999/BA/


GRB_name: GRB180102A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22301
SUBJECT: GRB 180102A: TSHAO optical upper limit
DATE:    18/01/03 17:34:05 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), A. Pozanenko (IKI), I. Reva (FAPHI), M. Krugov 
(FAPHI),  A. Volnova (IKI), A. Kusakin (FAPHI) report on behalf of 
larger GRB follow-up collaboration:

We observed the field of GRB 180102A (Page  et al., GCN 22292)   with 
Zeiss-1000 1-m telescope of Tien Shan Astronomical Observatory starting 
on Jan. 02 (UT) 21:34:54. We took several images in R-filter.  We do not 
detect any new sources within enhanced XRT error circle (Beardmore et 
al., GCN 22294).  Preliminary photometry of the field is following.

Date        UT start t-T0     Filter Exp.    OT    Err.  UL
                       (mid, days)    (s)

2018-01-02  21:34:54 0.25428  R      21*120  n/d   n/d   20.6


The photometry is based on several nearby USNO-B1.0 stars.


GRB_name: GRB171205A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22302
SUBJECT: VLBA detection of GRB 171205A
DATE:    18/01/05 18:39:30 GMT
FROM:    Miguel Perez-Torres at IAA-CSIC  <torres@iaa.es>

Miguel Perez-Torres (IAA-CSIC), S. Bradley Cenko (NASA), Assaf Horesh 
(HUJI),
and Antxon Alberdi (IAA-CSIC) report:

We observed GRB 171205A (D'Elia et al., GCN 22177) with the Very Long
Baseline Array (VLBA) on 2017 Dec 15.53 UT and 2017 Dec 16.56 at several
frequencies. We centered our observations at the VLA position of GRB 
171205A
(Laskar et al., GCN 22216), and imaged a region of (0.5x0.5) sq. arcsec 
around it.
At a frequency of 4.4 GHz, we detect GRB 171205A with a preliminary peak 
flux
density of ~2.3 mJy/beam at the following position:

RA  =  11:09:39.5179609
Dec = -12:35:18.459250

The (preliminary) uncertainty on the position of the peak flux density 
is of
~130 and ~50 microarcsec in RA and Dec, respectively.

More VLBI follow-up observations of GRB171205A are on the way.
We thank the NRAO staff for the time allocation and their help with the 
observations.


