TITLE: GCN CIRCULAR NUMBER: 40345 SUBJECT: GRB 250504A: Enhanced Swift-XRT position DATE: 25/05/05 07:32:59 GMT FROM: Phil Evans at U of Leicester pae9@star.le.ac.uk
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 940 s of XRT Photon Counting mode data and 2 UVOT images for GRB 250504A, 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 = 269.61806, -40.36676 which is equivalent to:
RA (J2000): 17h 58m 28.34s Dec (J2000): -40d 22' 00.3"
with an uncertainty of 4.0 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.
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