TITLE: GCN CIRCULAR NUMBER: 30623 SUBJECT: GRB 210807A: Swift-BAT refined analysis DATE: 21/08/10 01:41:52 GMT FROM: Sibasish Laha at GSFC T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 210807A (trigger #1064221) (Lien et al., GCN Circ. 30600). The BAT ground-calculated position is RA, Dec = 76.666, 58.257 deg which is RA(J2000) = 05h 06m 39.7s Dec(J2000) = +58d 15' 25.6" with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 28%. The BAT light curve showed a complex structure with a duration of about ~200 sec. T90 (15-350 keV) is 156.30 +- 214.60 sec (estimated error including systematics). The time-averaged spectrum from -19.544 to 640.052 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.26 +- 0.08. The fluence in the 15-150 keV band is 9.5 +- 0.4 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+70.52 sec in the 15-150 keV band is 1.8 +- 0.4 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/1064221/BA/