TITLE: GCN CIRCULAR NUMBER: 9585 SUBJECT: GRB 090628: Swift detection of a burst DATE: 09/06/28 21:42:02 GMT FROM: Scott Barthelmy at NASA/GSFC V. Mangano (INAF-IASFPA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), E. A. Hoversten (PSU), J. A. Kennea (PSU), D. M. Palmer (LANL), B. Sbarufatti (INAF-IASFPA), M. Stamatikos (NASA/ORAU) and M. A. Stark (PSU) report on behalf of the Swift Team: At 21:20:12 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 090628 (trigger=355942). Swift could not immediately slew to the burst. The BAT on-board calculated location is RA, Dec 237.050, -15.977 which is RA(J2000) = 15h 48m 12s Dec(J2000) = -15d 58' 36" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single peak structure with a duration of about 5 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. Due to an Earth limb constraint, a prompt slew was not possible. Swift will execute a delayed slew after 2656 s. No XRT or UVOT data will be available until the slew occurs. The series GCN Notices for this burst are corrupted with many (but not all) bogus values. For the moment, please disregard the original series of notices. We may issue Updated position notices when the information becomes available. Burst Advocate for this burst is V. Mangano (vanessa AT ifc.inaf.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.)