{
  "subject": "GRB 210517A: Enhanced Swift-XRT position",
  "eventId": "GRB 210517A",
  "bibcode": "2021GCN.30034....1B",
  "createdOn": 1621242644000,
  "circularId": 30034,
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "email": "pae9@leicester.ac.uk",
  "body": "A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) \nreport on behalf of the Swift-XRT team.\n\nUsing 1271 s of XRT Photon Counting mode data and 2 UVOT\nimages for GRB 210517A, we find an astrometrically corrected X-ray\nposition (using the XRT-UVOT alignment and matching UVOT field sources\nto the USNO-B1 catalogue): RA, Dec = 358.22445, -39.10218 which is equivalent\nto:\n\nRA (J2000): 23h 52m 53.87s\nDec (J2000): -39d 06' 07.9\"\n\nwith an uncertainty of 2.2 arcsec (radius, 90% confidence).\n\nThis position may be improved as more data are received. The latest\nposition can be viewed at http://www.swift.ac.uk/xrt_positions. Position\nenhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans\net al. (2009, MNRAS, 397, 1177).\n\nThis circular was automatically generated, and is an official product of the\nSwift-XRT team."
}