{
  "bibcode": "2007GCN..6814....1C",
  "body": "B. E. Cobb, part of the larger SMARTS consortium, reports:\n\nUsing the ANDICAM instrument on the 1.3m telescope at CTIO, we\nobtained optical imaging of the error region of GRB 070920b\n(Racusin et al. GCN 6808) with a mid-exposure time of ~4.4 hours\npost-burst (2007-09-21 01:29 UT).  The total summed exposure\ntime amounted to 36 minutes in I, but images were taken under poor\nweather conditions.\n\nComparison to the DSS reveals no new sources in the\nrefined GRB error region (Barthelmy et al. GCN 6811).\nOur I-band limiting magnitude is I~20.8 (calibrated using\nseveral USNO-B1.0 stars).",
  "circularId": 6814,
  "createdOn": 1190398289000,
  "email": "cobb@astro.yale.edu",
  "subject": "GRB 070920b, SMARTS optical observation",
  "submitter": "Bethany Cobb at Yale U  <cobb@astro.yale.edu>",
  "eventId": "GRB 070920B"
}