TITLE: GCN CIRCULAR NUMBER: 26982 SUBJECT: GRB 200205A: Swift detection of a burst with a possible UV counterpart DATE: 20/02/05 07:14:19 GMT FROM: Kim Page at U.of Leicester P. A. Evans (U Leicester), A. Y. Lien (GSFC/UMBC), K. L. Page (U Leicester), K. K. Simpson (PSU) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team: At 06:35:51 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 200205A (trigger=954304). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 130.171, -35.245 which is RA(J2000) = 08h 40m 41s Dec(J2000) = -35d 14' 39" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is usual with an image trigger, the available BAT light curve shows no significant structure. The XRT began observing the field at 06:38:07.9 UT, 136.3 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 130.1717, -35.2715 which is equivalent to: RA(J2000) = 08h 40m 41.21s Dec(J2000) = -35d 16' 17.4" with an uncertainty of 5.0 arcseconds (radius, 90% containment). This location is 95 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. The initial flux in the 2.5 s image was 3.00e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 250 seconds with the UVW2 filter starting 139 seconds after the BAT trigger. There is a possible UVOT counterpart close to the XRT position, but we cannot provide precise coordinates 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/)