TITLE: GCN CIRCULAR NUMBER: 16827 SUBJECT: GRB 140916A: Swift-BAT refined analysis DATE: 14/09/17 00:23:32 GMT FROM: Takanori Sakamoto at AGU M. Stamatikos (OSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), J. L. Racusin (NASA/GSFC), T. Sakamoto (AGU), J. Tueller (GSFC), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 140916A (trigger #612804) (Racusin, et al., GCN Circ. 16819). The BAT ground-calculated position is RA, Dec = 40.384, -39.688 deg which is RA(J2000) = 02h 41m 32.2s Dec(J2000) = -39d 41' 18.6" with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 16%. The mask-weighted light curve shows a single peak starting at T-3 sec, peaking at T+3 sec and ending at T+100 sec. T90 (15-350 keV) is 80.1 +- 15.6 sec (estimated error including systematics). The time-averaged spectrum from T-6.6 to T+89.5 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.15 +- 0.27. The fluence in the 15-150 keV band is 1.7 +- 0.3 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+1.80 sec in the 15-150 keV band is 1.3 +- 0.4 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/612804/BA/