TITLE: GCN CIRCULAR NUMBER: 15612 SUBJECT: GRB 131226A: Swift detection of a burst DATE: 13/12/26 06:01:22 GMT FROM: Mike Siegel at PSU/Swift MOC S. R. Oates (UCL-MSSL), H. A. Krimm (CRESST/GSFC/USRA), N. P. M. Kuin (UCL-MSSL) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 05:47:39 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 131226A (trigger=582123). The BAT on-board calculated location is RA, Dec 301.307, -64.962 which is RA(J2000) = 20h 05m 14s Dec(J2000) = -64d 57' 43" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of about 10 sec. The peak count rate was ~15000 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 2014 January 27. There will thus be no XRT or UVOT data for this trigger. Burst Advocate for this burst is S. R. Oates (samantha.oates AT ucl.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.)