TITLE: GCN CIRCULAR NUMBER: 30979 SUBJECT: GRB 211023B: Swift-BAT refined analysis DATE: 21/10/24 20:56:12 GMT FROM: Hans Krimm at NSF/NASA-GSFC <hkrimm@nsf.gov> S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), S. Dichiara (NASA/GSFC/UMCP), H. A. Krimm (NSF), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC), 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 211023B (trigger #1080859) (Dichiara, et al., GCN Circ. 30960). The BAT ground-calculated position is RA, Dec = 170.314, 39.133 deg which is RA(J2000) = 11h 21m 15.3s Dec(J2000) = +39d 07' 58.7" with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 48%. The mask-weighted light curves shows a single peak from approximately T+0 to T+1.5 seconds. T90 (15-350 keV) is 1.30 +- 0.26 sec (estimated error including systematics). The time-averaged spectrum from T-0.01 to T+1.45 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.97 +- 0.24. The fluence in the 15-150 keV band is 1.7 +- 0.3 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.24 sec in the 15-150 keV band is 2.2 +- 0.3 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/1080859/BA/