{
  "bibcode": "2015GCN.17590....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 observations of Swift\ntrigger 634795 (Hagen, et al., GCN 17573).  Our narrow-field instruments\nlocated in Los Alamos, NM, USA, arrived on target at 04:55:20.83 UT, T+27.98\nseconds after the BAT trigger time.  Our initial 5s exposure shows the\ncounterpart (Zheng, et al., GCN 17574) at an unfiltered magnitude of\n13.11 +- 0.02.  The source fades steadily, reaching magnitude 15.87 +- 0.09\nat T+180.38 s, in agreement with the KAIT lightcurve (Zheng, et al., GCN\n17585).  We derive a power-law decay slope of -1.50 using 04:54:52.86 as\nthe BAT T0.  Our unfiltered magnitudes were calibrated to the USNO-B1 R-band\ncatalog.\n\nThe optical counterpart is not detected in any of our persistent wide-field\nmonitors during the gamma-ray emitting interval.  Typical 3-sigma unfiltered\nlimiting magnitudes during this period were V~9.8 based on comparison to the\nTycho-2 V-band catalog.",
  "circularId": 17590,
  "createdOn": 1426553001000,
  "email": "jwren@lanl.gov",
  "subject": "GRB 150314A: Early RAPTOR Detection",
  "submitter": "James Wren at LANL  <jwren@lanl.gov>",
  "eventId": "GRB 150314A"
}