TITLE: GCN CIRCULAR NUMBER: 6792 SUBJECT: GRB 070917, Swift-BAT refined analysis DATE: 07/09/17 14:34:18 GMT FROM: Scott Barthelmy at NASA/GSFC J. Tueller (GSFC), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), T. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-120 to T+129 sec from the recent telemetry downlink, we report further analysis of BAT GRB 070917 (trigger #291292) (Cummings, et al., GCN Circ. 6791). The BAT ground-calculated position is RA, Dec = 293.923, 2.420 deg which is RA(J2000) = 19h 35m 41.5s Dec(J2000) = 02d 25' 12" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 79%. The mask-weighted lightcurve starts at ~T-5 sec, has a sharp rise from T-0.1 sec to ~T+0.3 sec, peaks at ~T+0.4 sec, and then approximately exponentially decays to background at ~T+30 sec. T90 (15-350 keV) is 7.3 +- 0.2 sec (estimated error including systematics). The time-averaged spectrum from T-0.1 to T+11.4 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.52 +- 0.05. The fluence in the 15-150 keV band is 2.0 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.21 sec in the 15-150 keV band is 8.5 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level.