TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4102 SUBJECT: GRB 051016: Swift-BAT refined analysis DATE: 05/10/16 17:34:48 GMT FROM: Scott Barthelmy at NASA/GSFC J. Tueller (GSFC), L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cannizzo (GSFC-UMBC), J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/NRC), G. Sato (ISAS), M. Tashiro (Saitama U.), on behalf of the Swift-BAT team: Using the data set from T-300 to T+300 sec from recent telemetry downlinks, we report further analysis of Swift-BAT GRB 051016 (trigger 159913) (Boyd, et al., GCN 4096). The refined BAT ground position is (RA,Dec) = 122.820, -18.309 deg {8h 11m 16.9s, -18d 18' 33.2"} (J2000) +- 2.0 arcmin, (radius, sys+stat, 90% containment). This position is 38 arcsec from the refined XRT position (Beardmore t al., GCN 4100). The partial coding was 18 %. The light curve shows a FRED-like peak. T90 (15-350 keV) is (22 +- 1) sec (estimated error including systematics). The power law index of the time-averaged spectrum is 1.88 +- 0.27. The fluence in the 15-150 keV band is (8.8 +- 1.4) x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T0+0.3 sec in the 15-150 keV band is (1.6 +- 0.4) ph/cm2/sec. All the quoted errors are at the 90% confidence level.