GCN Circular 22997
Subject
GRB 180721A: Enhanced Swift-XRT position
Date
2018-07-21T15:29:16Z (6 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1486 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 180721A, 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 = 347.71167, +4.85678 which is equivalent
to:
RA (J2000): 23h 10m 50.80s
Dec (J2000): +04d 51' 24.4"
with an uncertainty of 2.8 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 was automatically generated, and is an official product of the
Swift-XRT team.