{
  "bibcode": "2021GCN.29971....1E",
  "body": "P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), D.N. Burrows\n(PSU), J.A. Kennea (PSU), M. Perri (SSDC & INAF-OAR) and G. Tagliaferri\n(INAF-OAB) report on behalf of the Swift-XRT team:\n\nThe XRT began observing the field of GRB 210509A at 15:45:53.0 UT,\n4412.6 seconds after the BAT trigger. Using promptly downlinked data we\nfind an uncatalogued X-ray source located at RA, Dec 350.37430, 6.67134\nwhich is equivalent to:\n   RA(J2000)  = 23h 21m 29.83s\n   Dec(J2000) = +06d 40' 16.8\"\nwith an uncertainty of 4.4 arcseconds (radius, 90% containment). This\nlocation is 80 arcseconds from the BAT onboard position, within the BAT\nerror circle. This position may be improved as more data are received;\nthe latest position is available at https://www.swift.ac.uk/sper.  We\ncannot determine whether the source is fading at the present time. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density consistent with the Galactic value of 7.11\nx 10^20 cm^-2 (Willingale et al. 2013).",
  "circularId": 29971,
  "createdOn": 1620576418000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 210509A: Swift-XRT observations",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 210509A"
}