TITLE: GCN CIRCULAR NUMBER: 17159 SUBJECT: GRB 141212B: Swift detection of a burst DATE: 14/12/12 13:36:41 GMT FROM: Scott Barthelmy at NASA/GSFC M. Stamatikos (OSU/NASA/GSFC), S. D. Barthelmy (GSFC), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), B.P. Gompertz (U Leicester), J. A. Kennea (PSU), K. L. Page (U Leicester) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 13:23:48 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 141212B (trigger=621234). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 250.869, +31.749 which is RA(J2000) = 16h 43m 28s Dec(J2000) = +31d 44' 57" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a multiple-peak structure with a duration of about 15 sec. The peak count rate was ~7000 counts/sec (15-350 keV), at ~4 sec after the trigger. The XRT began observing the field at 13:25:13.4 UT, 85.2 seconds after the BAT trigger. No source was detected in the 2.5-s promptly available image. We are waiting for the full dataset to detect and localise the XRT counterpart. Burst Advocate for this burst is M. Stamatikos (Michael.Stamatikos-1 AT nasa.gov). 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.)