| Summary table |
|---|
| Variable |
Value |
Source |
| T0 |
14:36:06 UTC |
GCN_circulars,Swift Det |
| ra |
245.1249° |
Swift |
| decl |
-73.5407° |
Swift |
| pos_error |
1.94e-04° |
Swift |
| GBM_located |
False |
|
| mjd |
58773.608402777776 |
GCN_circulars,Swift Det |
| IPN table |
|---|
| GRB_name |
GRB191017B |
| ra |
245.1500° |
| decl |
-73.5667° |
| pos_error |
5.00e-02° |
| Swift table |
|---|
| GRB_name |
GRB191017B |
| t_trigger |
14:36:06 UTC |
| ra |
245.1249° |
| decl |
-73.5407° |
| pos_error |
1.94e-04° |
| GCN 26021 table |
|---|
| GRB_name |
GRB191017B |
| GCN_number |
26021 |
| Detection_method |
Swift Det |
| t_trigger |
14:36:06 UTC |
| ra |
245.1510° |
| decl |
-73.5610° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 26021
SUBJECT: GRB 191017B: Swift detection of a burst
DATE: 19/10/17 14:55:44 GMT
FROM: David Palmer at LANL
B. Sbarufatti (PSU), J.D. Gropp (PSU), J. A. Kennea (PSU),
N. J. Klingler (PSU), A. Y. Lien (GSFC/UMBC), M. J. Moss (GWU),
K. L. Page (U Leicester), D. M. Palmer (LANL) and
A. Tohuvavohu (Toronto) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 14:36:06 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 191017B (trigger=929981). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 245.151, -73.561 which is
RA(J2000) = 16h 20m 36s
Dec(J2000) = -73d 33' 40"
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 8 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 14:37:50.7 UT, 103.8 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 245.1255, -73.5404
which is equivalent to:
RA(J2000) = 16h 20m 30.13s
Dec(J2000) = -73d 32' 25.3"
with an uncertainty of 2.2 arcseconds (radius, 90% containment). This
location is 78 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 (9.84 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 3
(+3.00/-2.59) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 301 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
0.11.
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/)
|
| GCN 26022 table |
|---|
| GRB_name |
GRB191017B |
| GCN_number |
26022 |
| Detection_method |
Swift-XRT Det |
| ra |
245.1249° |
| decl |
-73.5407° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 26022
SUBJECT: GRB 191017B: Enhanced Swift-XRT position
DATE: 19/10/17 20:12:56 GMT
FROM: Phil Evans at U of Leicester
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team.
Using 759 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 191017B, 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 = 245.12493, -73.54074 which is equivalent
to:
RA (J2000): 16h 20m 29.98s
Dec (J2000): -73d 32' 26.7"
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.
|
| GCN 26027 table |
|---|
| GRB_name |
GRB191017B |
| GCN_number |
26027 |
| Detection_method |
Swift-XRT Other |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 26027
SUBJECT: GRB 191017B: Swift-XRT refined Analysis
DATE: 19/10/18 05:32:16 GMT
FROM: Phil Evans at U of Leicester
A.P. Beardmore (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA),
A. Melandri (INAF-OAB), D.N. Burrows (PSU), J. D. Gropp (PSU), A.
Tohuvavohu (U. Toronto), P.A. Evans (U. Leicester), J.P. Osborne (U.
Leicester) and B. Sbarufatti report on behalf of the Swift-XRT team:
We have analysed 6.1 ks of XRT data for GRB 191017B (Sbarufatti et al.
GCN Circ. 26021), from 256 s to 29.2 ks after the BAT trigger. The
data are entirely in Photon Counting (PC) mode. The enhanced XRT
position for this burst was given by Goad et al. (GCN Circ. 26022).
The light curve can be modelled with a power-law decay with a decay
index of alpha=0.64 (+/-0.05).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.54 (+0.20, -0.12). The
best-fitting absorption column is consistent with the Galactic value
of 9.8 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 4.4 x 10^-11 (4.9 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 9.8 (+/-6.9) x 10^20 cm^-2
Galactic foreground: 9.8 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index: 1.54 (+0.20, -0.12)
If the light curve continues to decay with a power-law decay index of
0.64, the count rate at T+24 hours will be 0.018 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.8 x
10^-13 (8.6 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/00929981.
This circular is an official product of the Swift-XRT team.
|
| GCN 26029 table |
|---|
| GRB_name |
GRB191017B |
| GCN_number |
26029 |
| Detection_method |
Swift-UVOT Other |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 26029
SUBJECT: GRB 191017B: Swift/UVOT Upper Limits
DATE: 19/10/18 14:37:28 GMT
FROM: Sam LaPorte at PSU
GRB 191017B: Swift/UVOT Upper Limits
J. D. Gropp (PSU) and B. Sbarufatti (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 191017B
302 s after the BAT trigger (Sbarufatti et al., GCN Circ. 26021).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 26022)
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 302 452 147 >18.9
white 302 1010 334 >19.1
v 460 4806 255 >18.1
b 558 752 39 >18.3
u 533 727 39 >18.9
w1 509 702 39 >18.2
m2 484 852 39 >18.6
w2 609 4601 235 >20.0
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).
|
| GCN 26030 table |
|---|
| GRB_name |
GRB191017B |
| GCN_number |
26030 |
| Detection_method |
Swift-BAT Det |
| ra |
245.1310° |
| decl |
-73.5830° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 26030
SUBJECT: GRB 191017B: Swift-BAT refined analysis
DATE: 19/10/18 23:37:15 GMT
FROM: Sibasish Laha at GSFC
J. R. Cummings (CPI), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), B. Sbarufatti (PSU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL),
S. D. Barthelmy (GSFC), (i.e. the Swift-BAT team):
Using the data set from T-82 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 191017B (trigger #929981)
(Sbarufatti et al., GCN Circ. 26021). The BAT ground-calculated position is
RA, Dec = 245.131, -73.583 deg which is
RA(J2000) = 16h 20m 31.3s
Dec(J2000) = -73d 34' 57.7"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 44%.
The mask weighted light curve shows a single peak structure with a duration of ~8 sec.
The overall structure starts at ~ T-2 sec and lasts till ~ T+6 sec.
T90 (15-350 keV) is 5.95 +- 1.28 sec (estimated error including systematics).
The time-averaged spectrum from T-1.34 to T+5.59 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.82 +- 0.20. The fluence in the 15-150 keV band is 5.6 +- 0.7 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.36 sec in the 15-150 keV band
is 1.9 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/929981/BA/
|