TITLE: GCN CIRCULAR NUMBER: 32854 SUBJECT: GRB 221024A: Swift-BAT refined analysis DATE: 22/10/26 14:47:54 GMT FROM: Hans Krimm at NSF/NASA-GSFC A. Y. Lien (U Tampa), S. D. Barthelmy (GSFC), R. Brivio (INAF-OAB), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), 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 221024A (trigger #1131029) (Brivio, et al., GCN Circ. 32827). The BAT ground-calculated position is RA, Dec = 169.702, 33.068 deg which is RA(J2000) = 11h 18m 48.6s Dec(J2000) = +33d 04' 04.9" with an uncertainty of 2.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 35%. The mask-weighted light curve shows a rather weak pulse starting at the trigger time, peaking around T+5 seconds and decaying to baseline by about T+40 seconds. There is some low-level emission following this peak, including a possible peak In the low-energy bands at approximately T+200 seconds. The pipeline-calculated T90 (15-350 keV) is 120+-111 sec (estimated error including systematics), with the large stated error due to uncertainty in whether the possible T+200 peak contains at least 5% of the burst fluence. The time-averaged spectrum from T+0.00 to T+221.28 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.39 +- 0.25. The fluence in the 15-150 keV band is 1.5 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+2.93 sec in the 15-150 keV band is 1.5 +- 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/1131029/BA/