GRB 100203A
GCN Circular 10360
Subject
GRB 100203A Detected in Ground Analysis of BAT Data
Date
2010-02-04T22:09:23Z (15 years ago)
From
Hans Krimm at NASA-GSFC <hans.krimm@nasa.gov>
J. R. Cummings (NASA/GSFC/CRESST), H. A. Krimm (NASA/GSFC/CRESST),
F. E. Marshall (GSFC), D. M. Palmer (LANL)
report on behalf of the Swift-BAT team:
At 18:31:07 UTC on Feb-03-2010, BAT triggered on GRB 100203A.
The source was detected onboard at a significance too low to trigger an
automated response. In ground analysis, a source was found at RA, Dec = 96.225,
+4.793, which is
RA (J2000) 06h 24m 54s
Dec (J2000) 4d 47' 33"
with an estimated uncertainty of 2 arcmin radius (90% containment).
The Galactic coordinates of the source are 205.629, -3.690. While the
event appears to be a faint, soft, long GRB, we cannot completely
discount the possibility of it being a Galactic transient.
The lightcurve shows 3 well-separated peaks, each about 10 seconds long,
at T-50, T+0, and T+60 seconds.
A 4 ksec follow-up observation with the Swift XRT and UVOT has been scheduled.
GCN Circular 10368
Subject
GRB 100203A: Swift XRT and UVOT refined analyses
Date
2010-02-05T16:44:31Z (15 years ago)
From
Rhaana Starling at U of Leicester <rlcs1@star.le.ac.uk>
R.L.C. Starling (U Leicester), E.A. Hoversten (PSU) and F.E.
Marshall (NASA/GSFC) report on behalf of the Swift XRT and
UVOT teams:
We observed the Swift GRB 100203A, detected in ground analysis
(Cummings et al. GCN Circ. 10360), with Swift XRT and UVOT
beginning 25.66 hours (92.3 ks) after the BAT trigger (#411011).
The XRT observed the field for 3.85 ks. No source has been detected at
the 3-sigma confidence level or above, with a 3-sigma upper limit on the
count rate at the BAT position of 6 x 10^-3 ct s^-1. We note that this
source lies near the Galactic Plane, where Galactic absorption in this
direction is high, at 5.3 x 10^21 cm^-2.
The UVOT observed the field of GRB 100203A in the uvm2 filter.
Visual comparison with DSS images of the field reveal no afterglow
candidates. Given the low Galactic latitude, afterglow detection
is complicated by high extinction and numerous bright stars in the
field.
The observed 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for initial exposures are:
Filter T_start(s) T_stop(s) Exp(s) 3-sigma upper limit
=============================================================
uvm2 92604 103268 3915 > 21.27
The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.55 in the direction of the burst
(Schlegel et al. 1998).
This circular is an official product of the Swift team.