TITLE: GCN CIRCULAR NUMBER: 17300 SUBJECT: GRB 150110B: Swift-BAT refined analysis DATE: 15/01/11 16:16:12 GMT FROM: Scott Barthelmy at NASA/GSFC H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), P. A. Evans (U Leicester), N. Gehrels (GSFC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), 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 recent telemetry downlinks, we report further analysis of BAT GRB 150110B (trigger #624606) (Evans, et al., GCN Circ. 17291). The BAT ground-calculated position is RA, Dec = 289.374, 32.529 deg, which is RA(J2000) = 19h 17m 29.7s Dec(J2000) = +32d 31' 43.2" with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 96%. The mask-weighted light curve shows two peaks starting at ~T-8 sec, peaking at ~T-5 and ~T+2 sec, and ending at ~T+10 sec. T90 (15-350 keV) is 10.6 +- 0.95 sec (estimated error including systematics). The time-averaged spectrum from T-7.94 to T+3.77 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.89 +- 0.13. The fluence in the 15-150 keV band is 4.9 +- 0.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+2.00 sec in the 15-150 keV band is 1.4 +- 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/624606/BA/