TITLE: GCN CIRCULAR NUMBER: 28995 SUBJECT: GRB 201203A: Swift-BAT refined analysis DATE: 20/12/04 23:07:12 GMT FROM: Sibasish Laha at GSFC T. Sakamoto (AGU), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), S. Dichiara (NASA/GSFC/UMCP), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-239 to T+130 sec from the recent telemetry downlink, we report further analysis of BAT GRB 201203A (trigger #1010946) (Dichiara et al., GCN Circ. 28985). The BAT ground-calculated position is RA, Dec = 38.055, -26.505 deg which is RA(J2000) = 02h 32m 13.1s Dec(J2000) = -26d 30' 19.2" with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 91%. The BAT light curve showed a complex structure with a duration of about ~20 sec. T90 (15-350 keV) is 12.18 +- 2.10 sec (estimated error including systematics). The time-averaged spectrum from T-2.73 to T+12.84 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.78 +- 0.26. The fluence in the 15-150 keV band is 2.9 +- 0.5 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T+11.49 sec in the 15-150 keV band is 0.5 +- 0.1 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/1010946/BA/