TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3360 SUBJECT: Swift-BAT detection of GRB050505 DATE: 05/05/06 00:15:29 GMT FROM: Scott Barthelmy at NASA/GSFC C. Hurkett (U. Leicester), S. Barthelmy (GSFC), J. Cummings (GSFC/NRC), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), P. Shady (MSSL), J. Osborne (U. Leicester), J. Kennea, D. Burrows (PSU) for the Swift-team: At 23:22:21 UT, the Swift Burst Alert Telescope (BAT) triggered and located on-board GRB050505 (trigger #117504). The BAT on-board calculated location is RA, Dec 141.782, +30.255 (J2000) with an uncertainty of 4 arcmin (radius, 3-sigma, including estimated systematic uncertainty, 90% containment). The BAT light curve showed a multipeak structure with a duration of about 45 seconds. The peak count rate measured by BAT was about 1500 counts/sec in the 15 - 350 keV band, occurring at the trigger. The Swift spacecraft did not make an immediate slew because of the Earth observing constraint. [GCN OPS NOTE(05May05): The author list was changed to include authors that were accidentally left out.]