{
  "bibcode": "2006GCN..5512....1C",
  "body": "S. B. Cenko and A. Rau (Caltech) report on behalf of a larger\ncollaboration:\n\nWe have imaged the error circle of GRB 060904a (Grupe et al; GCN 5502)\nwith the automated Palomar 60-inch telescope.  Observations began at\n4:57 UT 4 September (3.9 hours after the burst) and consisted of 12 x 180\ns images in the Kron R and Sloan i' and z' filters.  We find no sources\ninside the XRT error circle, to a limiting magnitude of R > 22.0\n(estimated by comparison with several USNO-B objects in the field).",
  "circularId": 5512,
  "createdOn": 1157355617000,
  "email": "cenko@srl.caltech.edu",
  "subject": "GRB 060904A: P60 Observations",
  "submitter": "S. Bradley Cenko at Caltech  <cenko@srl.caltech.edu>",
  "eventId": "GRB 060904A"
}