TITLE: GCN CIRCULAR NUMBER: 21196 SUBJECT: GRB 170604A: Enhanced Swift-XRT position DATE: 17/06/05 08:03:35 GMT FROM: Kim Page at U.of Leicester K.L. Page, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team: Using 4539 s of XRT Photon Counting mode data and 10 UVOT images, 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 = 342.65623, -15.41233 which is equivalent to: RA (J2000): 22 50 37.49 Dec (J2000): -15 24 44.4 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 is an official product of the Swift-XRT team.