TITLE: GCN CIRCULAR NUMBER: 43965 SUBJECT: GRB 260312A: Swift detection of a burst DATE: 26/03/12 03:17:24 GMT FROM: David Palmer at LANL <palmer@lanl.gov> N. J. Klingler (GSFC/UMBC/CRESSTII), C. Gronwall (PSU), R. Gupta (NASA GSFC), A. Y. Lien (U Tampa), M. J. Moss (GSFC), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 02:57:00 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 260312A (trigger=1500106). Swift did not slew. The BAT on-board calculated location is RA, Dec 351.609, -3.533 which is RA(J2000) = 23h 26m 26s Dec(J2000) = -03d 31' 59" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 30 sec. The peak count rate was ~500 counts/sec (15-350 keV), at ~0 sec after the trigger. Swift automatic follow-up slews are currently disabled. Thus there will be no XRT or UVOT data for this trigger, which is also Sun constrained. Although Swift could not slew to confirm the GRB with an X-ray afterglow, the high significance in the BAT image (9.4 sigma) gives us confidence that this is an astrophysical source. Burst Advocate for this burst is N. J. Klingler (noelklin AT umbc.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/43965. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...