{
  "bibcode": "2012GCN.13818....1W",
  "body": "J. Wren, W.T. Vestrand, P. Wozniak, and H. Davis,\nof Los Alamos National Laboratory report:\n\nThe RAPTOR network of robotic optical telescopes made follow-up observations\nof Swift trigger 534402 (Yershov, et al., GCN 13796).  Our narrow-field\ninstruments in Los Alamos, NM, began imaging at 05:17:43.06 UT, 96.8 s after\nthe Swift BAT trigger.  We do not detect the optical counterpart (Levan,\net al., GCN 13802) in any of our images.  The following table summarizes some\nof our early observations.  Our unfiltered images are calibrated to the\nUSNO-B1 r-band.  The start time is seconds since the BAT trigger time.  The\nmagnitude limit is the 3-sigma detection threshold.\n\nT-Start    Exp-Time   Mag-Limit\n----------------------------------\n96.82      5.9        17.3\n106.83     5.4        17.6\n143.24     5.4        17.5\n161.53     5.1        17.5\n181.82     10.1       18.2\n220.22     10.4       18.1\n284.22     10.9       18.1",
  "circularId": 13818,
  "createdOn": 1348616736000,
  "email": "jwren@nis.lanl.gov",
  "subject": "GRB 120923A: RAPTOR Early Afterglow Limits",
  "submitter": "James Wren at LANL  <jwren@nis.lanl.gov>",
  "eventId": "GRB 120923A"
}