TITLE: GCN CIRCULAR NUMBER: 15950 SUBJECT: GRB 140311B: Swift-XRT observations DATE: 14/03/11 23:07:34 GMT FROM: Phil Evans at U of Leicester J.P. Osborne (U. Leicester), D.N. Burrows (PSU), J.A. Kennea (PSU), G. Tagliaferri (INAF-OAB), S. Campana (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: The XRT began observing the field of GRB 140311B at 22:11:04.3 UT, 3394.7 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 252.32458, 52.72393 which is equivalent to: RA(J2000) = 16h 49m 17.90s Dec(J2000) = +52d 43' 26.1" with an uncertainty of 3.6 arcseconds (radius, 90% containment). This location is 110 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 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 3.03 x 10^20 cm^-2 (Kalberla et al. 2005).