{
  "bibcode": "2005GCN..3843....1M",
  "body": "Daryl Macomb, Jessica Elias (Boise State U.), \nJerry Bonnell, Alexander Kutyrev, Jay Norris (NASA/GSFC),\nand Ron Canterna, Mike Pierce (U. Wyoming) report:\n\nWe observed the position reported by Fox and Cenko (GCN 3829)\nof the afterglow for GRB 050820a (Swift trigger #151207, Page et al.,\nGCN 3830) with the 2.3-meter WIRO telescope.  Starting at 08:10 UT \n(96 minutes after the GRB trigger) and continuing until 11:30 UT, \nwe detected the fading afterglow in the J band in each of 120 40-s\nintegrations.  J magnitudes determined at the following times were\n(relative to burst trigger):\n\nEpoch   T-Ttrig     J mag\n  1      6240 s      16.0\n  2      9600 s      16.7\n  3     16020 s      16.9\n\nBetween epochs 1 and 2, the inferred average power-law decay index \nis -1.5, steeper than the -0.9 index reported by Cenko and Fox\n(GCN 3834) for the initial decay during the interval ~ 7 - 93 minutes \nafter the burst.  Between epoches 2 and 3, the average decay index \nflattens to -0.44, after which our observations ended due to twilight.\n\nThe times of the three reported epochs are arbitrary.  Detailed \nanalysis to yield accurate break times and indices is in progress.",
  "circularId": 3843,
  "createdOn": 1124603510000,
  "email": "dmacomb@boisestate.edu",
  "subject": "GRB 050820a: NIR Observations by WIRO",
  "submitter": "Daryl Macomb at Boise STate U  <dmacomb@boisestate.edu>",
  "eventId": "GRB 050820A"
}