TITLE: GCN CIRCULAR NUMBER: 38367 SUBJECT: GRB 241128A: Swift detection of a burst DATE: 24/11/28 16:37:44 GMT FROM: K.L. Page at U Leicester <klp5@leicester.ac.uk> R. Brivio (INAF-OAB), M. Ferro (INAF-OAB), C. Gronwall (PSU), R. Gupta (NASA GSFC), A. Y. Lien (U Tampa), K. L. Page (U Leicester), D. M. Palmer (LANL), C. Salvaggio (INAF-OAB) and T. Sbarrato (INAF-OAB) report on behalf of the Neil Gehrels Swift Observatory Team: At 16:14:34 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 241128A (trigger=1270999). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 273.724, +33.435 which is RA(J2000) = 18h 14m 54s Dec(J2000) = +33d 26' 07" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). Although a telemetry gap prevented the download of a BAT lightcurve, the trigger duration of 4 s indicates that this is a long burst. The XRT began observing the field at 16:16:32.2 UT, 118.0 seconds after the BAT trigger. No source was detected in the 2.5-s promptly available image. We are waiting for the full dataset to detect and localise the XRT counterpart. There are no prompt UVOT data available at this time. Although this source has not been confirmed during the short XRT observation (truncated by entrance into the SAA) or by the non-availability of the BAT lightcurve, the strength of peak (8.4 sigma) in the BAT image indicates that this is an astrophysical source. Burst Advocate for this burst is R. Brivio (riccardo.brivio 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/38367. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...