TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4288 SUBJECT: GRB 051117B: Refined analysis of the Swift-BAT burst DATE: 05/11/17 20:41:10 GMT FROM: Scott Barthelmy at NASA/GSFC A. Parsons (GSFC), L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (GSFC/UMD), K. Hurley (Berkeley), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), J. Norris (GSFC), D. Palmer (LANL), 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 GRB 051117B (trigger #164279) (Band, et al., GCN 4281). The ground-analysis position is RA,Dec 85.187,-19.280 {05h 40m 44.9s,-19d 16' 48.5"} (J2000) with an uncertainty of 2.5 arcmin (radius, 90%, stat+sys). T90 is 8 +- 1 sec. The partial coding fraction is 73%. The lightcurve has a bump of ~10 sec in duration with a peak at T+1 sec. Fitting a simple power law over the full interval from T-0.3 to T+7.5 sec, the photon index is 1.7 +/- 0.3 with a fluence of 1.4 +/- 0.3 X 10^-7 erg/cm^2. The peak flux in a 1-sec wide window starting at T+1.4 sec is 0.46 +/- 0.15 ph/cm^2/sec. All values are in the 15-150 keV band at the 90% confidence level.