TITLE: GCN CIRCULAR NUMBER: 18165 SUBJECT: GRB 150819A: Prompt enhanced Swift-XRT position DATE: 15/08/19 01:29:35 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Using promptly downlinked XRT event data for GRB 150819A, we find an enhanced XRT position of the afterglow: RA, Dec: 42.3335, 9.8075 which is equivalent to: RA (J2000) = 02 49 20.03 Dec (J2000) = +09 48 26.9 with an uncertainty of 2.0 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/652643. Position enhancement is 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.