TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2874 SUBJECT: Swift-BAT detection of the bright long burst GRB041219 DATE: 04/12/19 06:33:02 GMT FROM: Scott Barthelmy at NASA/GSFC S. Barthelmy (GSFC), D. Burrows (PSU), J. Cummings (GSFC), E. Fenimore (LANL), N. Gehrels (GSFC), M. Goad (U.Leicester), D. Hullinger (UMD), H. Krimm (USRA), C. Markwardt (UMD), F. Marshall (GSFC), K. McLean (LANL), J. Nousek (PSU), J. Osborne (U.Leicester), D. Palmer (LANL), A. Parsons (GSFC), G. Sato (ISAS), M. Suzuki (Saitama), G. Tagliaferri (OAB), J. Tueller (GSFC) on behalf of the Swift BAT team. At 01:42:18 UT, the Swift Burst Alert Telescope (BAT) triggered and located on-board GRB041219 (GCN Circ# 2866, D.Gotz et al.). The spacecraft did not autonomously slew to the burst since automated slewing is not yet enabled. The BAT ground-calculated location is RA,Dec 6.154,+62.847 (J2000) with an uncertainty of 12 arcmin (radius, including a large systematic uncertainty due to the lack of an on-orbit bore-sight alignment calibration). This is ~11 degrees off the BAT bore sight and is in the fully encoded field of view. This position is consistant with the INTEGRAL position (GCN Circ# 2866), and is within 4.1 arcmin of the BAT on-board location (14 sec after the initial rate trigger). We note that this position is in the Galactic plane with a Galactic Lon,Lat of 120,+0.1deg. The burst lightcurve is multi-peaked with structure within the peaks. After an initial pair of small precursors, the peak intensity increased to 25 events/cm^2/sec (1-sec sampling; unsaturated; ~15 to 200 keV; 43 Crab) 300 sec after the initial triggering peak. The total duration was 520 sec. The fluence is ~1e-4 erg/cm^2.