{
  "bibcode": "2005GCN..3604....1W",
  "body": "J. Wren, W.T. Vestrand, P. Wozniak, R. White, S. Evans report\non behalf of the RAPTOR team.\n\nThe RAPTOR-S telescope at Los Alamos National Laboratory began\nimaging the field of GRB 050713A (Swift trigger 145675) 22.4\nseconds after the GRB trigger -- before the end of the interval\nof prompt gamma-ray emission (Falcone et al. GCN circ 3581).\nAt the location of the fading optical and NIR counterpart identified\nin later images by Malesani et al. (GCN circ 3582) and Hearty et al.\n(GCN circ 3583), respectively, we detected a transient optical\ncounterpart.  In a stack of eight 10 second unfiltered images\nstarting at 04:29:24.8 UT (with midpoint at 99.3 s after the GRB\ntrigger), we measured the optical transient to have a R-band\nmagnitude of 18.4 (+/- 0.18).  Our preliminary transformation to\nR-band magnitudes was based on field stars from the USNO-B1 catalog.",
  "circularId": 3604,
  "createdOn": 1121296538000,
  "email": "jwren@nis.lanl.gov",
  "subject": "GRB 050713A: RAPTOR detection of early optical emission",
  "submitter": "James Wren at LANL  <jwren@nis.lanl.gov>",
  "eventId": "GRB 050713A"
}