{
  "bibcode": "2008GCN..8084....1R",
  "body": "E.S. Rykoff (UCSB), reports on behalf of the ROTSE collaboration:\n\nROTSE-IIIa, located at Siding Spring Observatory, Australia, responded\nto GRB 080810 (Swift trigger 319584, GCN 8080, Page et al.). The first\nimage was at 13:10:47.6 UT, 35.3 s after the burst (21.6 s after the\nGCN notice time), contemporaneous with the gamma-ray emission (GCN\n8082, Sakamoto et al.).  We took 10 5s exposures, 10 20s exposures,\nand 137 60s exposures under variable conditions.  The unfiltered\nimages are calibrated relative to USNO B1.0. We detect a 12.8\nmagnitude, variable source with coordinates:\n\n   23:47:10.5 +00:19:11.5 (J2000) (uncertainty of 1\" or better)\n\nstart UT        mag     mlim(of image)\n----------------------------------\n\n13:11:16.7     12.8     16.5\n\nThe position is consistent with the XRT and UVOT positions reported in\nGCN 8080.\n\nOur prompt detection shows the afterglow initially rising from 13.7\nmag (38s post-burst) to a peak of 12.8 mag (67s post-burst).  This is\nfollowed by a shallow decay from ~67s to ~230s (decay index\nalpha=-0.15+/-0.05), and a break to a steeper decay from ~230s to\n~6000s post-burst (decay index alpha=-1.13+/-0.02).  Preliminary\nanalysis does not show any significant deviations from this smooth\nevolution.\n\nA jpeg image is available at\nhttp://www.rotse.net/images/gsb319584_3a02_img.jpg\nThe object in question is marked with yellow and blue circles.",
  "circularId": 8084,
  "createdOn": 1218392977000,
  "email": "erykoff@physics.ucsb.edu",
  "subject": "GRB 080810: ROTSE-III Prompt Detection of Optical Counterpart",
  "submitter": "Eli Rykoff at UCSB  <erykoff@physics.ucsb.edu>",
  "eventId": "GRB 080810"
}