TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4269 SUBJECT: GRB 051113: Swift-BAT refined analysis DATE: 05/11/14 01:02:18 GMT FROM: Louis M Barbier at NASA/GSFC/Swift C. Markwardt (GSFC/UMD), L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (UMD), H. Krimm (GSFC/USRA), T. Mitani (ISAS), J. Nousek (PSU), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/NRC), G. Sato (ISAS), M. Suzuki (Saitama), M. Tripicco (GSFC-SSAI), J. Tueller (GSFC), on behalf of the Swift/BAT team: At 15:22:35 UT Swift-BAT detected GRB 051113 (trigger=163765) (GCN Circ 4268, Holland et al.). The refined BAT ground position is (RA,Dec) = 187.267, -26.387, [deg; J2000] {12h 29m 4.2s, -26d 23' 14"} +- 2 arcmin, (95% containment). The partial coding was 25%. The light curve shows multiple peaks at T-30 seconds, T, T+50 seconds, and T+70 seconds. T90 (15-350 keV) is (94 +- 1) seconds (estimated error including systematics). The photon index of the time-averaged spectrum is 1.70 +- 0.14. The fluence in the 15-150 keV band is (2.6 +- 0.2) x 10^-6 erg/cm2. The 1-s peak photon flux measured from T+ 1 second in the 15-350 band is (2.4 +- 0.3) ph/cm2/sec. All the quoted errors are at the 90% confidence level.