TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2918 SUBJECT: GRB041228: Swift-BAT detection of a burst DATE: 04/12/28 18:08:18 GMT FROM: Scott Barthelmy at NASA/GSFC 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.