TITLE: GCN CIRCULAR NUMBER: 13568 SUBJECT: GRB 120803A: Swift-BAT refined analysis DATE: 12/08/03 13:59:39 GMT FROM: Scott Barthelmy at NASA/GSFC T. N. Ukwatta (MSU), 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), D. M. Palmer (LANL), J. L. Racusin (NASA/GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC) (i.e. the Swift-BAT team): Using the data set from T-61 to T+242 sec from recent telemetry downlinks, we report further analysis of BAT GRB 120803A (trigger #529582) (Racusin, et al., GCN Circ. 13565). The BAT ground-calculated position is RA, Dec = 269.531, -6.733 deg, which is RA(J2000) = 17h 58m 07.4s Dec(J2000) = -06d 43' 58.0" with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 54%. The mask-weighted light curve shows a single peak starting at ~T+0, peaking ~T+3 sec, and returning to baseline at ~T+20 sec. T90 (15-350 keV) is 10.0 +- 3.6 sec (estimated error including systematics). The time-averaged spectrum from T+0.40 to T+11.40 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.86 +- 0.35. 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+3.40 sec in the 15-150 keV band is 0.4 +- 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/529582/BA/ We note that in our original circular (13565) that this event was labeled as a "possible" GRB. Given that the BAT detection significance in ground proccessing has risen to 8.0 sigma, that the lightcurve shape is consistant with a GRB, and that it is off the Galactic Plane, we are confident that this trigger is due to a real GRB.