{
  "bibcode": "2007GCN..6151....1R",
  "body": "J. Racusin (PSU), M. Goad (U. Leicester), D.N. Burrows (PSU), O. Godet (U. \nLeicester), R. Starling (U. Leicester) report on behalf of the Swift XRT \nteam:\n\nBased on an accurate mapping between the XRT and UVOT detector coordinate \nsystems, we have used the simultaneous UVOT V-band images to \nastrometrically correct (relative to stellar catalogues, e.g. USNO-B1) the \nXRT world coordinate system, and thereby refine the XRT position.  We \nobtain a new XRT position at RA,Dec=179.02792,-13.3304 which is:\n\nRA(J2000):  11h 56m 06.7s\nDec(J2000): -13d 19' 49.6\"\n\nwith an uncertainty of 2.6 arcseconds (90% containment).  This is 3.8 \narcseconds from the refined XRT position (Racusin et al., GCN 6143), and \n2.0 arcseconds from the optical candidate first identified by Thoene et \nal. (GCN 6142).\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 6151,
  "createdOn": 1172517750000,
  "email": "racusin@astro.psu.edu",
  "subject": "GRB070224: Swift-XRT Astrometrically Corrected Position",
  "submitter": "Judith Racusin at PSU  <racusin@astro.psu.edu>",
  "eventId": "GRB 070224"
}