TITLE:   GCN CIRCULAR
NUMBER:  10872
SUBJECT: GRB 100621A: Prompt enhanced Swift-XRT position
DATE:    10/06/21 03:56:48 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

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.