{
  "subject": "GRB 100305A Optical Observations",
  "eventId": "GRB 100305A",
  "bibcode": "2010GCN.10475....1H",
  "createdOn": 1267801021000,
  "circularId": 10475,
  "submitter": "Arne A. Henden at AAVSO  <arne@aavso.org>",
  "email": "arne@aavso.org",
  "body": "A. Henden (AAVSO), J. Gross (SRO), B. Denny (DC-3), D. Terrell (SwRI), and\nW. Cooney (SRO) report:\n\nWe obtained imagery of the GRB 100305A burst reported by Troja et al.\n(GCN 10470) using the Sonoita Research Observatory (SRO) 35cm telescope\nin southern Arizona, utilizing an automatic VOevent trigger.  The\nexposures began about 3 minutes after the burst and continued\nfor approximately two hours.  20 Rc-band, 10 V-band, and a set of\nBVRI exposures for field calibration were acquired.\nInspection of the enhanced Swift-XRT position given by Osborne, et al.\n(GCN 10474) does not show any optical afterglow to the following limits,\nbased on using star USNOB 1323-0268523 at 11:13:38.45 +42:23:45.7\nas having magnitudes R=15.98 and V=16.67):\n\nUTmid     delT    exp   filt  lim\n(hrs)     (min)  (# x s)\n09.1544  003.63  01x060  Rc  19.1\n09.2379  008.64  10x060  Rc  20.5\n09.4821  023.29  05x180  Rc  21.3\n09.8411  044.83  05x300  Rc  21.6\n10.8564  105.75  10x300  V   21.1\n\nThe AAVSO thanks the Curry Foundation for its support of the AAVSO\nInternational High Energy Network."
}