TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2952 SUBJECT: GRB050117: Swift-BAT detection of a long multi-peaked burst DATE: 05/01/17 14:57:54 GMT FROM: Scott Barthelmy at NASA/GSFC T. Sakamoto (GSFC), S. Barthelmy, L. Barbier (GSFC), A. Blustin (MSSL), J. Cummings (GSFC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (GSFC/UMD), J. Kennea (PSU) H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (LANL), T. McMahon (Langston U.), D. Palmer (LANL), A. Parsons (GSFC), G. Sato (ISAS), P. Schady (MSSL), M. Suzuki (Saitama), J. Tueller (GSFC) on behalf of the Swift-BAT team: At 12:52:36 UT, the Swift Burst Alert Telescope (BAT) triggered and located on-board GRB050117. The spacecraft autonomously slewed to the burst for the first time with a real GRB. The BAT on-board calculated location is RA,Dec 358.427,+65.945 (J2000) with an uncertainty of 4 arcmin (radius, 3-sigma, including a systematic uncertainty). This is within 55 arcsec of the XRT position (Burrows et al., GCN Circ 2951). This burst occurred while Swift was near the SAA. The lightcurve is multi-peaked with a duration of ~200 sec. We note that the XRT was on target during the later portion of the gamma-ray phase of the burst.