TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3665 SUBJECT: GRB050724: a short-burst detected by Swift DATE: 05/07/24 13:34:04 GMT FROM: Stefano Covino at Brera Astronomical Observatory S. Covino (INAF/OAB), L.A. Antonelli (INAF/OAR), P. Romano (INAF/OAB), D. Palmer (LANL), C. Markwardt(GSFC, UMd), D. Burrows (PSU), N. Gehrels (GSFC), S. Barthelmy (GSFC), M. Chester (PSU), S. Hunsberger (PSU), J. Cummings (GSFC/NRC) on behalf of the Swift team At 12:34:09 UT, Swift-BAT triggered and located GRB050724 (trigger=147478). The spacecraft slewed immediately. The BAT on-board calculated location is RA,Dec 246.214, -27.524 {+16h 24m 51s, -27d 31' 25"} (J2000), with an uncertainty of 3 arcmin (radius, 90% containment, stat+sys). The light curve appears to be short, with full-width half maximum of less than 0.25 sec, and a peak rate of 10,000 ct/s in that interval. The XRT started the observation at 12:35:22.9 UT with XRT in automatic state, 74 sec after the BAT Trigger. A rapidly fading, uncatalogued, X- ray source was detected at the following position RA, Dec 16h 24m 44.9s, -27d 32' 34.0" with an uncertainty of about 6 arcsec (90% containment). This is 1.78 arcmin from the BAT position reported above. This message can be cited.