GCN Circular 13034
P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), D.N. Burrows (PSU), J.A. Kennea (PSU), M. Perri (ASDC) and G. Tagliaferri (INAF-OAB) report on behalf of the Swift-XRT team: The XRT began observing the field of GRB 120311A at 06:26:19.9 UT, 3161.6 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 273.08966, 14.29709 which is equivalent to: RA(J2000) = 18h 12m 21.52s Dec(J2000) = +14d 17' 49.5" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 80 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 in excess of the Galactic value (1.03 x 10^21 cm^-2, Kalberla et al. 2005), with an excess column of 2.5 (+2.12/-1.86) x 10^21 cm^-2 (90% confidence).