TITLE: GCN CIRCULAR NUMBER: 35101 SUBJECT: GRB 231118A: Swift detection of a burst DATE: 23/11/18 17:31:56 GMT FROM: David Palmer at LANL S. Laha (GSFC/UMBC), M. Ferro (INAF-OAB), C. Gronwall (PSU), M. J. Moss (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), T. M. Parsotan (GSFC/UMBC/CRESSTII), T. Sbarrato (INAF-OAB), M. H. Siegel (PSU) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team: At 17:16:33 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 231118A (trigger=1197311). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 4.843, -48.035 which is RA(J2000) = 00h 19m 22s Dec(J2000) = -48d 02' 07" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 15 sec. The peak count rate was ~11,000 counts/sec (15-350 keV), at ~0 sec after the trigger. Due to a telemetry outage, XRT and UVOT data are not immediately available and will be reported later. Burst Advocate for this burst is S. Laha (sib.laha AT gmail.com). 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/)