TITLE: GCN CIRCULAR NUMBER: 7250 SUBJECT: GRB 080205: Swift detection of a burst DATE: 08/02/05 08:21:36 GMT FROM: David Palmer at LANL C. B. Markwardt (CRESST/GSFC/UMD), M. M. Chester (PSU), J. R. Cummings (NASA/UMBC), P. A. Evans (U Leicester), A. D. Falcone (PSU), N. Gehrels (NASA/GSFC), C. Guidorzi (INAF-OAB), S. T. Holland (CRESST/USRA/GSFC), S. D. Hunsberger (PSU), J. A. Kennea (PSU), C. Pagani (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL), D. Perez (U Leicester), J. L. Racusin (PSU), T. Sakamoto (NASA/UMBC), M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the Swift Team: At 07:55:51 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 080205 (trigger=302506). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 98.219, +62.769 which is RA(J2000) = 06h 32m 53s Dec(J2000) = +62d 46' 07" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows three roughly equal-height peaks spanning approximately 120 seconds. The peak count rate was ~1000 counts/sec (15-350 keV), at ~0 sec, ~70 sec, and ~95 sec after the trigger. XRT began observing at 07:57:32 UT, 101 s after the BAT trigger. Using prompt downlinked data, we find a bright, fading, uncatalogued X-ray source located at RA, Dec 98.2561, 62.7913 deg which is RA(J2000) = 06h 33m 1.46s Dec(J2000) = +62d 47' 30.1" with an uncertainty of 3.0 arcsec (radius, 90% containment). This location is 100 arcseconds from the BAT on-board position, within the BAT error circle. UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm) filter starting 112 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The 3-sigma upper limit at the XRT position is 19.2 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.09. Burst Advocate for this burst is C. B. Markwardt (craigm AT milkyway.gsfc.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.)