{
  "bibcode": "2001GCN..1100....1H",
  "body": "A. Henden (USRA/USNO) reports on behalf of the USNO GRB team:\n\nWe have acquired UBVRcIc all-sky photometry for\nan 11x11 arcmin field that covers the center of the\nerror box for GRB010921 (GCN 1096,1097) with the USNOFS 1.0-m telescope\non one photometric night.  Stars brighter than\nV=13.5 are saturated and should be used with care.\nWe have placed the photometric data on our anonymous ftp site:\nftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb010921.dat\nThe current photometry has a potential external zero-point\nerror of about two percent.  The astrometry in this file\nis based on linear plate solutions with respect to USNO-A2.0.\nThe internal errors are less than 100mas.\nFurther calibration of this field will be performed if\nan optical afterglow is identified.",
  "circularId": 1100,
  "createdOn": 1001182127000,
  "email": "aah@nofs.navy.mil",
  "subject": "GRB010921 field photometry",
  "submitter": "Arne A. Henden at USNO/USRA  <aah@nofs.navy.mil>",
  "eventId": "GRB 010921"
}