TITLE: GCN CIRCULAR NUMBER: 35501 SUBJECT: GRB 240109A: Swift detection of a short burst DATE: 24/01/09 04:15:10 GMT FROM: David Palmer at LANL <palmer@lanl.gov> S. Dichiara (PSU), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 04:01:35 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 240109A (trigger=1207446). Due to a Sun constraint, Swift did not slew immediately to the burst. The BAT on-board calculated location is RA, Dec 301.318, +16.578 which is RA(J2000) = 20h 05m 16s Dec(J2000) = +16d 34' 39" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single spike structure with a duration of about 0.25 sec. The peak count rate was ~4000 counts/sec (15-350 keV), at ~0.1 sec after the trigger. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 00:14 UT on 2024 March 01. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is S. Dichiara (sbd5667 AT psu.edu). 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/35501. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...