TITLE: GCN CIRCULAR NUMBER: 36851 SUBJECT: GRB 240712A: Swift detection of a burst DATE: 24/07/12 04:05:15 GMT FROM: David Palmer at LANL <palmer@lanl.gov> C. Salvaggio (INAF-OAB), N. P. M. Kuin (UCL-MSSL), D. M. Palmer (LANL), T. Sbarrato (INAF-OAB) and B. Sbarufatti (INAF-OAB) report on behalf of the Neil Gehrels Swift Observatory Team: At 03:27:12 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 240712A (trigger=1242223). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 122.369, -37.077 which is RA(J2000) = 08h 09m 29s Dec(J2000) = -37d 04' 35" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve before T+8s after the trigger is unavailable due to a telemetry outage. The burst triggered on the 8s timescale indicating that it is a long burst, but no other duration information is presently available. The XRT began observing the field at 03:29:47 UT, 155 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 122.3378, -37.0923 which is equivalent to: RA(hh mm ss.s) = 8h09m21.08s Dec(dd mm ss.s) = -37:05:32.21 with an uncertainty of 6.4 arcseconds (radius, 90% containment). This location is 105 arcseconds from the BAT onboard position, within the BAT error circle. UVOT took a finding chart exposure of 150 seconds with the White filter starting 140 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the large, but uncertain, extinction expected. Burst Advocate for this burst is C. Salvaggio (chiara.salvaggio AT 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/) View this GCN Circular online at https://gcn.nasa.gov/circulars/36851. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...