TITLE: GCN CIRCULAR NUMBER: 6943 SUBJECT: GRB 071018: Swift-XRT observation DATE: 07/10/19 16:28:50 GMT FROM: Andy Beardmore at U Leicester A.P. Beardmore, K.L. Page, P.A. Evans, R.L.C. Starling, J.P. Osborne (U. Leicester) and H.A Krimm (GSFC/USRA) report on behalf of the Swift-XRT team: The Swift-XRT began observing the field of the BAT GRB 071018 (trigger #294645) at 2007-10-19T00:36, 57 ks after the trigger. A photon counting mode image containing an exposure time of 4.0 ks reveals two faint uncatalogued sources: Source 1 is at RA, Dec (J2000) = 164.51244, 53.82275, which is RA(J2000) = 10 58 02.99 Dec(J2000) = +53 49 21.9 with an estimated uncertainty of 6.4 arcsec (radius, 90 percent confidence). This is 4.25 arcmin away from the refined BAT position of Sato et al. (GCN 6933), but outside the quoted BAT 2.7 arcmin 90 percent error circle. Its estimated count rate is (3.2+/-0.9)e-3 count s^-1. Source 2 is at RA, Dec (J2000) = 164.58083, 53.82383, which is RA(J2000) = 10 58 19.40 Dec(J2000) = +53 49 25.8 with an estimated uncertainty of 7.9 arcsec (radius, 90 percent confidence). This is 2.37 arcmin away from the refined BAT position and within its error circle. Its estimated count rate is (2.0+/-0.8)e-3 count s^-1. At this stage we cannot tell whether either source is fading and therefore associated with the GRB. Further observations are planned by Swift over the weekend. This circular is an official product of the Swift-XRT team.