GRB 200919A
GCN Circular 28454
Subject
GRB 200919A: Swift detection of a burst
Date
2020-09-19T02:00:19Z (5 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
T. N. Ukwatta (LANL), D. N. Burrows (PSU), V. D'Elia (SSDC),
S. Laha (GSFC/UMBC/CRESST), D. M. Palmer (LANL), B. Sbarufatti (PSU)
and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels
Swift Observatory Team:
At 01:52:20 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200919A (trigger=996503). Swift did not slew due to an
observing constraint. The BAT on-board calculated location is
RA, Dec 168.916, +32.457 which is
RA(J2000) = 11h 15m 40s
Dec(J2000) = +32d 27' 25"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a single complex peak
structure with a duration of about 40 sec. The peak count rate
was ~1600 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 05:40 UT on 2020 October 10. 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/)
GCN Circular 28458
Subject
GRB 200919A: Swift-BAT refined analysis
Date
2020-09-19T17:27:57Z (5 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), 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 200919A
(trigger #996503) (Ukwatta et al., GCN Circ. 28454).
The BAT ground-calculated position is
RA, Dec = 168.899, 32.456 deg which is
RA(J2000) = 11h 15m 35.7s
Dec(J2000) = +32d 27' 21.8"
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 62%.
The mask-weighted light curve shows several overlapping pulses
that start at ~T-60 s and end at ~T+25 s. The main peak
occurs at ~T+5 s. T90 (15-350 keV) is 76.0 +- 6.9 sec
(estimated error including systematics).
The time-averaged spectrum from T-61.47 to T+24.54 sec is best fit
by a simple power-law model. The power law index of the time-averaged
spectrum is 2.13 +- 0.14. The fluence in the 15-150 keV band
is 1.8 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured
from T+4.30 sec in the 15-150 keV band is 1.2 +- 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/996503/BA/
GCN Circular 28460
Subject
GRB 200919A: CrAO/ZTSh early optical upper limit
Date
2020-09-19T21:12:19Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI), V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on
behalf of IKI-GRB-FuN:
We observed the GRB 200919A (Ukwatta et al., GCN 28454) with ZTSH 2.6m
telescope of CrAO observatory starting on 2020-09-19 (UT) 02:26:25. We
do not detect any new evident object in the BAT GRB 200919A localization
field (Ukwatta et al., GCN 28454).
Preliminary photometry of the field is following
Date UT start t-T0 Filter Exp. OT Err. UL
(mid, days) (s)
2020-09-19 02:26:25 0.02541 R 30*10 n/d n/d 19.8
The photometry is based on nearby USNO-B1.0 stars
USNO-B1.0_id R2
1224-0243383 15.75
1224-0243414 15.12