TITLE: GCN CIRCULAR NUMBER: 12015 SUBJECT: GRB 110519A: Swift detection of a burst DATE: 11/05/19 02:26:31 GMT FROM: Scott Barthelmy at NASA/GSFC C. J. Saxton (UCL-MSSL), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC), H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (NASA/GSFC), S. R. Oates (UCL-MSSL), K. L. Page (U Leicester), D. M. Palmer (LANL), M. H. Siegel (PSU) and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift Team: At 02:12:16 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 110519A (trigger=453628). Swift did not slew because of a Moon observing constraint. The BAT on-board calculated location is RA, Dec 261.629, -23.408 which is RA(J2000) = 17h 26m 31s Dec(J2000) = -23d 24' 29" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a FRED pulse with a duration of about 35 sec. The peak count rate was ~4000 counts/sec (15-350 keV), at ~1 sec after the trigger. Due to a Moon observing constraint, Swift cannot slew to the BAT position until 23:19 UT on 2011 May 20. There will thus be no XRT or UVOT data for this trigger before this time. Although we note that this location is within 10 degrees of the Galactic center, we believe that this is very likely a cosmological GRB due to the strength of its emission above 100 keV. Burst Advocate for this burst is C. J. Saxton (cjs2 AT mssl.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.)