TITLE: GCN CIRCULAR NUMBER: 18683 SUBJECT: GRB 151210A: Swift-BAT refined analysis DATE: 15/12/10 14:08:52 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), P. A. Evans (U Leicester), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), 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-239 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 151210A (trigger #666931) (Evans, et al., GCN Circ. 18678). The BAT ground-calculated position is RA, Dec = 65.080, -71.225 deg, which is RA(J2000) = 04h 20m 19.1s Dec(J2000) = -71d 13' 28.9" with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 60%. The mask-weighted light curve shows several peaks starting at ~T-55 sec, with the brightest peaks at ~T+14 and ~T+38 sec, and ending at ~T+60sec. T90 (15-350 keV) is 94.9 +- 10.4 sec (estimated error including systematics). The time-averaged spectrum from T-57.19 to T+48.36 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.82 +- 0.79, and Epeak of 49.4 +- 15.3 keV (chi squared 53.7 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 1.3 +- 0.2 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+38.82 sec in the 15-150 keV band is 0.8 +- 0.2 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.83 +- 0.15 (chi squared 59.89 for 57 d.o.f.). 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/666931/BA/