TITLE: GCN CIRCULAR NUMBER: 27778 SUBJECT: GRB 200522A: Swift detection of a short burst DATE: 20/05/22 12:02:37 GMT FROM: Kim Page at U.of Leicester P. A. Evans (U Leicester), J.D. Gropp (PSU), S. Laha (GSFC/UMBC/CRESST), A. Y. Lien (GSFC/UMBC) and K. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift Observatory Team: At 11:41:34 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 200522A (trigger=973628). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 5.667, -0.282 which is RA(J2000) = 00h 22m 40s Dec(J2000) = -00d 16' 53" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 1 sec. The peak count rate was ~5000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 11:42:57.5 UT, 83.4 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 5.6823, -0.2824 which is equivalent to: RA(J2000) = 00h 22m 43.76s Dec(J2000) = -00d 16' 56.7" with an uncertainty of 3.9 arcseconds (radius, 90% containment). This location is 55 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data does not constrain the column density. No UVOT analysis is available at this time. Burst Advocate for this burst is P. A. Evans (pae9 AT star.le.ac.uk). 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/)