TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4063 SUBJECT: GRB051006: Refined analysis of the Swift-BAT burst DATE: 05/10/06 23:15:49 GMT FROM: Scott Barthelmy at NASA/GSFC D. Palmer (LANL), L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC), K. Gendreau (GSFC), D. Hullinger (GSFC/UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), P. Meszaros (PSU), A. Parsons (GSFC), T. Sakamoto (GSFC/NRC), G. Sato (ISAS), J. Tueller (GSFC) on behalf of the Swift-BAT team: Using the full data set from the recent telemetry downlink, we report further analysis of Swift-BAT Trigger #158593 (Norris, et al., GCN 4061). The ground-analysis position is RA,Dec 110.808,+9.510 {7h 23m 13.8s,+9d 30' 36.3"} (J2000) with an uncertainty of 1.7 arcmin (radius, 90%, stat+sys). T90 is 26 +- 1 sec. The lightcurve has an initial cluster of 3 overlapping peaks at T-5 to T+8 sec and a fourth peak at T+20 sec. Fitting a simple power law over the full interval from T-5.9 to T+24.7 sec, the photon index is 1.4 +/- 0.2 with a fluence of 1.28 +/- 0.13 X 10^-6 erg/cm^2. The peak flux in a 1-sec wide window starting at T+3.2 sec is 1.9 +/- 0.3 ph/cm^2/sec. All values are in the 15-150 keV band at the 90% confidence level.