TITLE: GCN CIRCULAR NUMBER: 28454 SUBJECT: GRB 200919A: Swift detection of a burst DATE: 20/09/19 02:00:19 GMT FROM: David Palmer at LANL T. N. Ukwatta (LANL), D. N. Burrows (PSU), V. D'Elia (SSDC), S. Laha (GSFC/UMBC/CRESST), D. M. Palmer (LANL), B. Sbarufatti (PSU) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team: At 01:52:20 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 200919A (trigger=996503). Swift did not slew due to an observing constraint. The BAT on-board calculated location is RA, Dec 168.916, +32.457 which is RA(J2000) = 11h 15m 40s Dec(J2000) = +32d 27' 25" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single complex peak structure with a duration of about 40 sec. The peak count rate was ~1600 counts/sec (15-350 keV), at ~0 sec after the trigger. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 05:40 UT on 2020 October 10. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com). 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/)