TITLE: GCN CIRCULAR NUMBER: 7013 SUBJECT: GRB 071028, Swift-BAT refined analysis DATE: 07/10/28 21:31:20 GMT FROM: Scott Barthelmy at NASA/GSFC J. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), J. L. Racusin (PSU), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+541 sec from the recent telemetry downlink, we report further analysis of BAT GRB 071028 (trigger #295527) (Racusin, et al., GCN Circ. 7012). The BAT ground-calculated position is RA, Dec = 119.828, 21.473 deg, which is RA(J2000) = 07h 59m 18.6s Dec(J2000) = 21d 28' 22" with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows a single FRED-like peak starting at ~T_zero, peaking at ~T+35 sec, and ending at ~T+110 sec. T90 (15-350 keV) is 27.0 +- 1.0 sec (estimated error including systematics). The time-averaged spectrum from T+19.2 to T+48.9 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.87 +- 0.26. The fluence in the 15-150 keV band is 3.0 +- 0.5 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+41.75 sec in the 15-150 keV band is 0.3 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level.