TITLE: GCN CIRCULAR NUMBER: 16155 SUBJECT: GRB 140423A: Enhanced Swift-XRT position DATE: 14/04/23 18:17:20 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 5971 s of XRT Photon Counting mode data and 15 UVOT images for GRB 140423A, 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 = 197.28544, +49.84152 which is equivalent to: RA (J2000): 13h 09m 8.51s Dec (J2000): +49d 50' 29.5" with an uncertainty of 1.4 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.