TITLE: GCN CIRCULAR NUMBER: 23651 SUBJECT: GRB 190109B: Swift-XRT observations DATE: 19/01/09 13:21:11 GMT FROM: Phil Evans at U of Leicester D.N. Burrows (PSU), J.A. Kennea (PSU), S. Campana (INAF-OAB), G. Cusumano (INAF-IASF PA), P.A. Evans (U. Leicester) and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team: The XRT began observing the field of GRB 190109B at 11:57:36.3 UT, 87.1 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 55.4870, 63.5920 which is equivalent to: RA(J2000) = 03h 41m 56.88s Dec(J2000) = +63d 35' 31.2" with an uncertainty of 2.1 arcseconds (radius, 90% containment). This location is 180 arcseconds from the BAT onboard position, outside the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 4.56 x 10^21 cm^-2 (Willingale et al. 2013).