GCN Circular 31275
Subject
GRB 211221A: Enhanced Swift-XRT position
Date
2021-12-22T01:29:16Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team.
Using 892 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 211221A, 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 = 78.89745, +0.91449 which is equivalent
to:
RA (J2000): 05h 15m 35.39s
Dec (J2000): +00d 54' 52.2"
with an uncertainty of 2.2 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.