TITLE: GCN CIRCULAR NUMBER: 18527 SUBJECT: GRB 151029A: Swift-BAT refined analysis DATE: 15/10/29 12:22:22 GMT FROM: Scott Barthelmy at NASA/GSFC M. Stamatikos (OSU), S. D. Barthelmy (GSFC), 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), T. Sakamoto (AGU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 151029A (trigger #662086) (Ukwatta, et al., GCN Circ. 18522). The BAT ground-calculated position is RA, Dec = 38.537, -35.356 deg, which is RA(J2000) = 02h 34m 09.0s Dec(J2000) = -35d 21' 21.7" with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 41%. The mask-weighted light curve shows two overlapping peaks starting at ~T-2 sec, peaking at ~T+1 se, and ending at ~T+10 sec. T90 (15-350 keV) is 8.95 +- 2.32 sec (estimated error including systematics). The time-averaged spectrum from T-1.10 to T+10.47 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.49 +- 1.08, and Epeak of 33.9 +- 6.9 keV (chi squared 53.8 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 3.9 +- 0.6 x 10^-7 erg/cm2 and the 1-sec peak flux measured from T-0.15 sec in the 15-150 keV band is 1.8 +- 0.3 ph/cm2/sec. A fit to a simple power law gives a photon index of 2.16 +- 0.19 (chi squared 64.3 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/662086/BA/