[vsnet-grb-info 28466] GRB210731A: Enhanced Swift-XRT position

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30569
SUBJECT: GRB210731A: Enhanced Swift-XRT position
DATE:    21/08/01 09:24:41 GMT
FROM:    Antonino D'Ai at IASF-PA  <antonino.dai at inaf.it>

Antonino D'Ai (INAF-iASFPA), P.A. Evans and M.R. Goad (U. Leicester) report
on behalf of the Swift-XRT team:

Using 963 s of XRT Photon Counting mode data and 4 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 =
300.30500, -28.06105 which is equivalent to:

RA (J2000):  20 01 13.20
Dec (J2000): -28 03 39.8

with an uncertainty of 2.6 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.