TITLE: GCN CIRCULAR NUMBER: 23525 SUBJECT: GRB 181213A: Swift detection of a burst DATE: 18/12/13 13:08:00 GMT FROM: Scott Barthelmy at NASA/GSFC P. A. Evans (U Leicester), S. D. Barthelmy (GSFC), J.D. Gropp (PSU), K. L. Page (U Leicester) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 12:57:38 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 181213A (trigger=876016). Swift will slew at ~T+33 min due to an observing constraint. The BAT on-board calculated location is RA, Dec 248.207, +78.504, which is RA(J2000) = 16h 32m 50s Dec(J2000) = +78d 30' 16" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows multiple peaks with a total duration of about 25 sec. The peak count rate was ~850 counts/sec (15-350 keV), at ~1 sec after the trigger. Due to an observing constraint, Swift will not slew until T0+33.8 minutes. There will be no XRT or UVOT data until this time. Burst Advocate for this burst is P. A. Evans (pae9 AT star.le.ac.uk). 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.)