GCN Circular 10872
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Using 0 s of promptly downlinked XRT event data for GRB 100621A, we find an enhanced XRT position of the afterglow: RA, Dec: 315.3052, -51.1060 which is equivalent to: RA (J2000) = 21 01 13.24 Dec (J2000) = -51 06 21.7 with an uncertainty of 2.0 arc sec (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/425151. 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.