TITLE: GCN CIRCULAR NUMBER: 8240 SUBJECT: GRB 080916B: Swift detection of a burst DATE: 08/09/16 14:55:24 GMT FROM: Jamie A. Kennea at PSU/Swift-XRT G. Stratta (ASDC), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), C. Guidorzi (INAF-OAB), S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU), S. D. Hunsberger (PSU), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), J. Mao (INAF-OAB), C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester), S. R. Oates (UCL-MSSL), J. P. Osborne (U Leicester), K. L. Page (U Leicester), M. Perri (ASDC), B. Preger (ASDC), R. L. C. Starling (U Leicester), M. C. Stroh (PSU) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team: At 14:44:47 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 080916B (trigger=324907). The BAT on-board calculated location is RA, Dec 163.624, +69.044 which is RA(J2000) = 10h 54m 30s Dec(J2000) = +69d 02' 39" 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 50 sec. The peak count rate was ~750 counts/sec (15-350 keV), at ~0 sec after the trigger. Due to an observing constraint, Swift will not slew until T0+18.9 minutes. There will be no XRT or UVOT data until this time. Burst Advocate for this burst is G. Stratta (giulia.stratta AT asdc.asi.it). 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.)