GCN Circular 3264
Subject
Swift BAT/XRT Detection of GRB 050416
Date
2005-04-16T11:50:53Z (20 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori@milkyway.gsfc.nasa.gov>
T. Sakamoto (GSFC/NRC), L. Barbier (GSFC), S. Barthelmy (GSFC),
D. Burrows (PSU), M. Chester (PSU), J. Cummings (GSFC/NRC),
E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (UMD),
J. Kennea (PSU) , H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
D. Palmer (LANL), A. Parsons (GSFC), G. Sato (ISAS), M. Suzuki (Saitama),
M. Tripicco (GSFC-SSAI), J. Tueller (GSFC), D. Burrows (PSU),
on behalf of the Swift team:
At 11:04:44.5 UT, the Swift Burst Alert Telescope (BAT) triggered and
located on-board GRB050416 (trigger #114753). The BAT on-board
calculated location is RA, dec 188.478, 21.043 (J2000) with an
uncertainty of 3.00 arcmin (radius, 3-sigma, including estimated
systematic uncertainty). The BAT light curve shows double
structures with a duration of about three seconds. The peak
count rate measured by BAT was about 3000 counts/sec in the 15 -
350 keV band. The burst signal is mostly seen in 15-50 keV.
The XRT observed the target field at 11:06:12 UT and detected 17 counts in
a single CCD frame, just under the number needed for a reliable on-board
centroid. Initial indications based on the raw spectra and lightcurve
transmitted via TDRSS suggest that there is a real X-ray source in the
field. We will issue an update following the next ground station pass at
12:18 UT.