GCN Circular 21862
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Using promptly downlinked XRT event data for GRB 170912A, we find an enhanced XRT position of the afterglow: RA, Dec: 167.3734, -54.3262 which is equivalent to: RA (J2000) = 11 09 29.61 Dec (J2000) = -54 19 34.4 with an uncertainty of 2.2 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/772006. 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.