Gamma-ray Burst 041220

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN notice #2890
  H. Krimm (GSFC/USRA), L. Angelini (GSFC/JHU), L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cummings (GSFC), E. Fenimore (LANL), N. Gehrels (GSFC), M. Goad (U.Leicester), D. Hullinger (GSFC/UMD), C. Markwardt (GSFC/UMD), K. McLean (LANL/UTD), D. Palmer (LANL), A. Parsons (GSFC), P. Roming (PSU), G. Sato (ISAS), M. Suzuki (Saitama), T. Takashima (ISAS), J. Tueller (GSFC) on behalf of the Swift BAT team:
  At 22:58:26 UT, the Swift-BAT triggered and located on-board GRB041220 (BAT Trigger #100433). The spacecraft did not autonomously slew to the burst since automated slewing is not yet enabled. Automated notification to the BAT Team through TDRSS was partially enabled for this burst.
  The ground-calculated location is RA, DEC 291.286, +60.624 (J2000) with an uncertainty of 12 arcmin (radius, dominated by a large systematic uncertainty due to the lack of an on-orbit boresight alignment calibration). This is ~16 degrees off the BAT boresight. It was imaged at >22 sigma. The source is 19 degrees off the galactic plane.
  The burst is a fast-rise exponential-decay (FRED) with a full-width at half-max of ~2 sec. There is some indication of emission out to 18 sec after the peak. The peak flux was 2.2 events/cm^2/sec in the 15-350 keV band (~8 Crab). The total fluence is approximately 5.9 events/cm^2 (15-350 keV), or 1E-6 erg/cm^2.