{
  "bibcode": "2008GCN..7374....1W",
  "body": "J. Wren, W.T. Vestrand, P.R. Wozniak, H. Davis\nof Los Alamos National Laboratory report:\n\nOur Raptor telescopes responded to Swift trigger 305011\n(Holland et al., GCN 7362) at 11:24:30.8 UTC, 60.0 seconds\nafter the trigger and 7.3 seconds after receipt of the GCN\npacket.  We detect no new optical source at the Swift XRT\nposition.  Five sigma limiting magnitudes are given for\nthree of our unfiltered response images in the table below.\nCalibration was performed using the USNO B1.0 R-band\nmagnitudes.\n\nT-start (UTC)           T-exp (s)    mag limit\n-------------------------------------------------\n2008-03-07 11:24:30.81    5            16.9\n2008-03-07 11:25:53.96    10           17.3\n2008-03-07 11:30:12.01    30           18.0",
  "circularId": 7374,
  "createdOn": 1204916358000,
  "email": "jwren@nis.lanl.gov",
  "subject": "GRB 080307: Early RAPTOR Limits",
  "submitter": "James Wren at LANL  <jwren@nis.lanl.gov>",
  "eventId": "GRB 080307"
}