TITLE: GCN CIRCULAR NUMBER: 8387 SUBJECT: GRB 081016B, Swift-BAT refined analysis DATE: 08/10/17 21:37:05 GMT FROM: Hans Krimm at NASA-GSFC M. Stamatikos (GSFC/ORAU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD), K. L. Page (U Leicester),D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), J. Tueller (GSFC), T. N. Ukwatta (GWU) (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 081016B (trigger #331856) (Page, et al., GCN Circ. 8381). The BAT ground-calculated position is RA, Dec = 14.582, -43.536 deg which is RA(J2000) = 00h 58m 19.8s Dec(J2000) = -43d 32' 07.9" with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 98%. The BAT mask-weighted light curve showed a single peak of duration ~2.5 seconds. T90 (15-350 keV) is 2.6 +- 0.8 sec (estimated error including systematics). The time-averaged spectrum from T-0.0 to T+3.0 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.92 +- 0.32. The fluence in the 15-150 keV band is 9.9 +- 1.8 x 10-08 erg/cm2. The 1-sec peak photon flux measured from T+0.50 sec in the 15-150 keV band is 0.5 +- 0.1 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/331856/BA/