TITLE: GCN CIRCULAR NUMBER: 17768 SUBJECT: GRB 150428A: Enhanced Swift-XRT position DATE: 15/04/28 05:34:00 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 147 s of XRT Photon Counting mode data and 1 UVOT images for GRB 150428A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 188.53878, +6.95390 which is equivalent to: RA (J2000): 12h 34m 9.31s Dec (J2000): +06d 57' 14.0" with an uncertainty of 1.9 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team.