GRB 191001B
GCN Circular 25902
Subject
GRB 191001B: Swift detection of a burst
Date
2019-10-01T17:39:17Z (6 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@milkyway.gsfc.nasa.gov>
E. Troja (NASA/GSFC/UMCP), E. Ambrosi (INAF-IASFPA),
S. D. Barthelmy (GSFC), V. D'Elia (SSDC), J. A. Kennea (PSU),
N. J. Klingler (PSU), F. E. Marshall (NASA/GSFC), M. J. Moss (GWU),
B. Sbarufatti (PSU) and A. Tohuvavohu (Toronto) report on behalf of
the Neil Gehrels Swift Observatory Team:
At 17:19:20 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 191001B (trigger=927345). Swift did not slew due to
targets with higher priority. The BAT on-board calculated location is
RA, Dec 86.368, -15.907 which is
RA(J2000) = 05h 45m 28s
Dec(J2000) = -15d 54' 25"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows several peaks
with a total duration of about 25 sec. The peak count rate
was ~1600 counts/sec (15-350 keV), at ~20 sec after the trigger.
Due to higher priority observations, Swift will not slew to the BAT position.
There will thus be no prompt XRT or UVOT data for this trigger.
Burst Advocate for this burst is E. Troja (eleonora.troja 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/)
GCN Circular 25906
Subject
GRB 191001B: MITSuME Akeno optical upper limits
Date
2019-10-01T18:52:08Z (6 years ago)
From
Katsuhiro L. Murata at Nagoya U <murata@u.phys.nagoya-u.ac.jp>
K. L. Murata, R. Adachi, M. Oeda, K.Shiraishi, K. Iida, M. Niwano,
F. Ogawa, R. Hosokawa, S. Toma, Y. Yatsu, and N. Kawai (TokyoTech)
report on behalf of the MITSuME collaboration:
We searched for the optical counterpart of GRB 191001B (E. Troja et
al., GCN Circular #25902) 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 17:22:09 UT. We did not find any new point
sources within the BAT on-board calculated error circle in all three bands.
We obtained the following 5-sigma limits for the magnitudes.
T0+[sec] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
~169 ~17:37 1680 g'>18.8, Rc>18.8, Ic>18.6
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.
The magnitudes are expressed in the AB system.
GCN Circular 25930
Subject
GRB 191001B: Swift-BAT refined analysis
Date
2019-10-02T23:53:19Z (6 years ago)
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),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), T. Sakamoto (AGU),
M. Stamatikos (OSU), E. Troja (NASA/GSFC/UMCP),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+962 sec from the recent telemetry
downlink,
we report further analysis of BAT GRB 191001B (trigger #927345)
(Troja et al., GCN Circ. 25902). The BAT ground-calculated position is
RA, Dec = 86.423, -15.880 deg which is
RA(J2000) = 05h 45m 41.5s
Dec(J2000) = -15d 52' 48.3"
with an uncertainty of 3.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 33%.
The mask-weighted light curve shows a multi-peaked structure that starts
at ~T-10 s and ends at ~T+130 s. T90 (15-350 keV) is 108.9 +- 15.1 sec
(estimated error including systematics).
The time-averaged spectrum from T-8.77 to T+126.11 sec is best fit by a
simple
power-law model. The power law index of the time-averaged spectrum is
1.58 +- 0.11. The fluence in the 15-150 keV band is 4.6 +- 0.3 x 10^-6
erg/cm2.
The 1-sec peak photon flux measured from T+20.44 sec in the 15-150 keV band
is 1.8 +- 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/927345/BA/
GCN Circular 25940
Subject
GRB 191001B: Optical Upper Limits with LCO
Date
2019-10-03T18:30:36Z (6 years ago)
From
Robert Strausbaugh at U. of the Virgin Islands <robert.strausbaugh@uvi.edu>
R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:
We observed Swift GRB 191001B (Barthelmy et al., GCN 25902) with the LCO 1-m Sinistro instrument on October 2, from 01:23 to 01:47 UT (corresponding to 5.73 to 6.2 hours from the GRB trigger time) with the SDSS r� and i� filters.
We performed a series of 5x120s exposures in each band. We do not detect any fading sources over the course of our observations in a 26.5' x 26.5' field of view centered around the Swift coordinates (Barthelmy et al., GCN 25902). Using the USNO-B.1 catalog as reference, we obtain the following 3-sigma upper limits:
r > 18.82
i > 16.98
These observations were possible thanks to the USVI NASA-EPSCoR Research Infrastructure Development (RID) grant NNX16AL44A.