Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. See news and announcements

GCN Circular 2898

GRB041223: Swift-BAT detection of a bright long burst
2004-12-23T17:58:52Z (19 years ago)
Scott Barthelmy at NASA/GSFC <>
J. Tueller, L. Barbier, S. Barthelmy (GSFC), A. Beardmore (U.Leicester),
L. Cominsky (Sonoma State U), J. Cummings (GSFC), E. Fenimore (LANL),
N. Gehrels (GSFC), S.T. Holland (GSFC/USRA), D. Hullinger (GSFC/UMD),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean, D. Palmer (LANL),
A. Parsons (GSFC), G. Sato (ISAS), M. Suzuki (Saitama), G. Tagliaferri (OAB)
on behalf of the Swift BAT team:

At 14:06:18 UT, the Swift Burst Alert Telescope (BAT) triggered and
located on-board GRB041223.  The spacecraft did not autonomously slew
to the burst since automated slewing was not yet enabled.

The BAT ground-calculated location is RA,Dec 100.183,-37.066 (J2000)
with an uncertainty of 7 arcmin (radius, 3-sigma, including systematic
uncertainty using a preliminary bore-sight alignment calibration).
This is 27 degrees off the BAT bore sight and was in the partially encoded
field of view.

The burst lightcurve is multi-peaked with structure within the peaks
with the main emission lasting ~60 sec.  The peak flux was 7.5 events/cm^2/sec
(1-sec sampling; unsaturated; ~15 to 100 keV; ~28 Crab).
The total duration was ~130 sec.  The fluence was ~2e-5erg/cm^2.
A reduced energy band is being quoted because of our response uncertainty
in the >100 keV band, and because of strong emission by this burst 
in this band.
Looking for U.S. government information and services? Visit