GRB 041228
GCN Circular 2918
Subject
GRB041228: Swift-BAT detection of a burst
Date
2004-12-28T18:08:18Z (20 years ago)
From
Scott Barthelmy at NASA/GSFC <Scott@lheamail.gsfc.nasa.gov>
A. Parsons, S. Barthelmy, L. Barbier (GSFC), S. Campana (OAB),
J. Cummings (GSFC), E. Fenimore (LANL), N. Gehrels (GSFC),
J. Hill (PSU), D. Hullinger (GSFC/UMD), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), F. Marshall (GSFC), K. McLean (LANL),
D. Palmer (LANL), T. Sakamoto (GSFC), G. Sato (ISAS), M. Suzuki (Saitama),
M. Tashiro (Saitama), J. Tueller (GSFC)
on behalf of the Swift-BAT team:
At 10:49:13 UT, the Swift Burst Alert Telescope (BAT) triggered and
located on-board GRB041228. The spacecraft did not autonomously slew
to the burst since automated slewing was not yet enabled.
The BAT ground-calculated location is RA,Dec 336.641,+5.050 (J2000)
with an uncertainty of 5 arcmin (radius, 3-sigma, including a systematic
uncertainty). The lightcurve is multi-peaked with a main emission duration
of ~40 s, with 36 counts/cm^2 fluence and a peak (1 second interval)
of ~1.2 counts/cm^2/s in the 15-350 keV band. And there appears to be
extended emission for another 80 sec.
GCN Circular 2919
Subject
GRB041228: ROTSE-III Optical Observations
Date
2004-12-28T20:03:23Z (20 years ago)
From
Eli Rykoff at U of Michigan/ROTSE <erykoff@umich.edu>
E. Rykoff (U. Michigan) reports on behalf of the ROTSE collaboration:
ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia,
responded to Swift GRB041228 (GCN #2918). An automatic response was
initiated during early twilight hours. The first usable image was taken
at 28 Dec 18:38:44 UT, 7.8 hours after the burst. We took 50 60-s
exposures before the burst position dropped below our minimum observing
elevation. The unfiltered images were calibrated relative to USNO A2.0.
Individual images have limiting magnitudes ranging from 17-18 as the
sky darkened. Comparison to DSS (second epoch) reveals no new sources
within the 3-sigma error circle to a limiting magnitude of 18.8 for
stacks of 10 images taken 8.4 hours after the burst.