TITLE: GCN CIRCULAR NUMBER: 17688 SUBJECT: GRB 150413A: Swift detection of a burst DATE: 15/04/13 14:06:39 GMT FROM: David Palmer at LANL C. B. Markwardt (NASA/GSFC), M. M. Chester (PSU), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), C. Pagani (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL) and T. N. Ukwatta (LANL) report on behalf of the Swift Team: At 13:54:58 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 150413A (trigger=637899). Swift did not slew immediately to the burst due to an observing constraint. The BAT on-board calculated location is RA, Dec 190.385, +71.824 which is RA(J2000) = 12h 41m 32s Dec(J2000) = +71d 49' 26" 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 120 sec. The peak count rate was ~1100 counts/sec (15-350 keV), at ~2 sec after the trigger. Due to an observing constraint, Swift cannot observe until T0+4 days. There will be no XRT or UVOT data until this time. Burst Advocate for this burst is C. B. Markwardt (Craig.Markwardt 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.)