TITLE: GCN CIRCULAR NUMBER: 5360 SUBJECT: GRB 060728: Swift detection of a burst DATE: 06/07/28 23:07:24 GMT FROM: Scott Barthelmy at NASA/GSFC C. Pagani (PSU), L. M. Barbier (NASA/GSFC), S. D. Barthelmy (GSFC), M. M. Chester (PSU), J. R. Cummings (NASA/UMD), C. B. Markwardt (GSFC/UMD), K. M. McLean (LANL/UTD), A. N. Morgan (PSU), D. M. Palmer (LANL) and M. Stamatikos (NASA/ORAU) report on behalf of the Swift Team: At 22:24:30 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 060728 (trigger=221627). Swift slewed immediately to the burst. The BAT on-board calculated location is RA,Dec 16.694, -41.386 {01h 06m 46s, -41d 23' 10"} (J2000) with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). This is an 64-sec image trigger so there is very little information in the TDRSS lightcuve. The XRT began taking data at 22:26:35 UT, 124 seconds after the BAT trigger. The XRT on-board centroid algorithm did not find a source in the image and no prompt position is available. We are waiting for down-linked data to detect and determine a position for the source. The UVOT began observing at 22:26:31.7 UT, 121.1 seconds after the BAT trigger. Images have been taken in V only, not in white, due to a bright source in the field-of-view. Ground processing indicates an uncataloged, non-fading source, V=16.93, 58 arcsecs from the BAT position. We are currently in the Malindi gap in data downlinks, so it will be about 6 hours until we get the full data set.