TITLE: GCN CIRCULAR NUMBER: 30980 SUBJECT: GRB 211024B: Swift detection of a burst DATE: 21/10/24 22:34:22 GMT FROM: David Palmer at LANL J.D. Gropp (PSU), N. J. Klingler (GSFC/UMBC/CRESSTII), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), D. M. Palmer (LANL), T. M. Parsotan (GSFC/UMBC/CRESSTII), M. H. Siegel (PSU) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team: At 22:20:36 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 211024B (trigger=1081073). Swift slewed immediately to the burst, but immediately slewed away due to a conflicting observation. The BAT on-board calculated location is RA, Dec 154.688, +24.579 which is RA(J2000) = 10h 18m 45s Dec(J2000) = +24d 34' 43" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 70 sec. The peak count rate was ~1500 counts/sec (15-350 keV), at ~7 sec after the trigger. Because of a conflicting preplanned observation, there was no immediate XRT or UVOT observation. A target of opportunity observation is planned. Burst Advocate for this burst is J.D. Gropp (jdg44 AT psu.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)