TITLE: GCN CIRCULAR NUMBER: 26012 SUBJECT: GRB 191016A: Swift-BAT refined analysis DATE: 19/10/16 21:40:40 GMT FROM: Sibasish Laha at GSFC S. D. Barthelmy (GSFC), J. R. Cummings (CPI), J.D. Gropp (PSU), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 191016A (trigger #929744) (Gropp et al., GCN Circ. 26008). The BAT ground-calculated position is RA, Dec = 30.268, 24.508 deg which is RA(J2000) = 02h 01m 04.4s Dec(J2000) = +24d 30' 30.4" with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 64%. The mask weighted light curve shows two overlapping pulses. Overall structure starts at ~ T-40 s and lasts till ~ T+420 s. The two peaks occur at ~ T-10 s and ~ T+35 s, respectively. T90 (15-350 keV) is 219.70 +- 183.35 sec (estimated error including systematics). The time-averaged spectrum from T-42.82 to T+422.61 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.55 +- 0.09. The fluence in the 15-150 keV band is 6.5 +- 0.4 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T-7.75 sec in the 15-150 keV band is 1.5 +- 0.2 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/929744/BA/