TITLE: GCN CIRCULAR NUMBER: 35448 SUBJECT: GRB 240101A: Swift detection of a burst DATE: 24/01/01 14:45:57 GMT FROM: K.L. Page at U Leicester <klp5@leicester.ac.uk> S. B. Cenko (GSFC), C. Gronwall (PSU), J.D. Gropp (PSU) and K. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift Observatory Team: The Swift Burst Alert Telescope (BAT) triggered and located GRB 240101A (trigger=1205708), and Swift has slewed to this burst. The trigger time is believed to be no earlier than 12:52 UT. Given the loss of some of the TDRSS notices, we will not have values for T0 or the BAT Position until the full data have been downloaded, in approximately 1.25 hours (by around 16:05 UT). Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 10.34819, 8.51706 which is equivalent to: RA(J2000) = 00h 41m 23.57s Dec(J2000) = +08d 31' 01.4" with an uncertainty of 1.9 arcseconds (radius, 90% containment). This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (5.84 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 1.1 (+0.67/-0.52) x 10^22 cm^-2 (90% confidence). No afterglow is detected in the initial UVOT data products. Burst Advocate for this burst is S. B. Cenko (brad.cenko AT nasa.gov). 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/35448. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...