GCN Circular 39977
Subject
GRB 250331C: Enhanced Swift-XRT position
Date
2025-03-31T16:38:10Z (3 days ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1624 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 250331C, 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 = 80.95619, +33.06347 which is equivalent
to:
RA (J2000): 05h 23m 49.49s
Dec (J2000): +33d 03' 48.5"
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.