TITLE: GCN CIRCULAR NUMBER: 12962 SUBJECT: GRB 120218A: Swift detection of a burst DATE: 12/02/18 00:59:33 GMT FROM: Scott Barthelmy at NASA/GSFC C. A. Wolf (PSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), N. Gehrels (NASA/GSFC), J. A. Kennea (PSU), C. B. Markwardt (NASA/GSFC), D. M. Palmer (LANL), C. J. Saxton (UCL-MSSL), B. Sbarufatti (INAF-OAB/PSU), C. A. Swenson (PSU), T. N. Ukwatta (MSU) and B.-B. Zhang (PSU) report on behalf of the Swift Team: At 00:49:22 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 120218A (trigger=515277). Swift did not slew due to a Sun constraint. The BAT on-board calculated location is RA, Dec 319.758, -25.450, which is RA(J2000) = 21h 19m 02s Dec(J2000) = -25d 27' 00" 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 30 sec. The peak count rate was ~3500 counts/sec (15-350 keV), at ~2 sec after the trigger. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 19:14 UT on 2012 March 20. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is C. A. Wolf (cwolf AT swift.psu.edu). 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.)