TITLE: GCN CIRCULAR NUMBER: 23448 SUBJECT: GRB 181125A: Swift detection of a burst DATE: 18/11/25 09:07:44 GMT FROM: Scott Barthelmy at NASA/GSFC E. Sonbas (Adiyaman Univ.), S. D. Barthelmy (GSFC), P. D'Avanzo (INAF-OAB), A. Y. Lien (GSFC/UMBC), A. Melandri (INAF-OAB) and K. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift Observatory Team: At 08:54:39 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 181125A (trigger=873433). Swift did not slew due to an observing constraint. The BAT on-board calculated location is RA, Dec 268.413, -2.613, which is RA(J2000) = 17h 53m 39s Dec(J2000) = -02d 36' 47" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single peak with a duration of about 10 sec. The peak count rate was ~1400 counts/sec (15-350 keV), at ~1 sec after the trigger. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 15:18 UT on 2019 January 31. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is E. Sonbas (edasonbas AT yahoo.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/too.html.)