{
  "bibcode": "2009GCN..9478....1W",
  "body": "J. Wren, W.T. Vestrand, P.R. Wozniak, H. Davis, B. Norman\nof Los Alamos National Laboratory report:\n\nThe RAPTOR telescope system responded to Swift trigger\n353567 (Cannizzo et al., GCN 9438) under fair observing conditions.\nOur narrow-field instruments began observing the location at\n03:18:37.96 UTC, 19.6 s after the Swift trigger.  We detect the\noptical counterpart initially reported by Cannizzo et al. (GCN 9438)\nand Flewelling et al. (GCN 9439).  Our first image at T+22.1 seconds\nshows the counterpart at R~17.1.  It appears to brighten over the\nnext minute reaching a peak near R~16.3 and then begins fading in\nthe manner described by Schady et al. (GCN 9450) and Rossi et al.\n(GCN 9458).  Our unfiltered images were calibrated against the\nUSNO-B1 R-band.  The following table gives selected observations,\nnot corrected for extinction, from this event.\n\nt-mid(s)    exp(s)     mag     mag-err\n--------------------------------------------\n22.08        5.0      17.13    0.25\n57.90        5.0      16.30    0.10\n84.50        5.0      16.60    0.13\n133.21      10.0      16.87    0.11\n414.65      30.0      17.31    0.09",
  "circularId": 9478,
  "createdOn": 1243903028000,
  "email": "jwren@nis.lanl.gov",
  "subject": "GRB 090530: Early RAPTOR Optical Observations",
  "submitter": "James Wren at LANL  <jwren@nis.lanl.gov>",
  "eventId": "GRB 090530"
}