TITLE: GCN CIRCULAR NUMBER: 31189 SUBJECT: GRB 211207A: Swift-BAT refined analysis DATE: 21/12/08 17:51:09 GMT FROM: Tyler Parsotan at UMBC/GSFC/CRESST II T. Sakamoto (AGU), S. D. Barthelmy (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC), M. Stamatikos (OSU), (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 211207A (trigger #1088376) (Ambrosi et al., GCN 31182). The BAT ground-calculated position is RA, Dec = 149.601, -24.360 deg which is RA(J2000) = 09h 58m 24.1s Dec(J2000) = -24d 21' 37.3" with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 62%. The BAT light curve showed a complex structure with a duration of about 4 sec. T90 (15-350 keV) is 3.73 +- 0.87 sec (estimated error including systematics). The time-averaged spectrum from T-1.30 to T+2.97 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.72 +- 0.30. The fluence in the 15-150 keV band is 1.9 +- 0.4 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T-0.15 sec in the 15-150 keV band is 0.9 +- 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/1088376/BA/