{
  "bibcode": "2009GCN.10058....1P",
  "body": "D. A. Perley (UC Berkeley) reports:\n\nI observed the location of GRB 091020 (Racusin et al, GCN 10048) \nstarting at UT 2009-10-21 12:30 using the Nickel 40-inch telescope at \nLick Observatory.   A series of nine exposures in R-band were acquired, \nfollowed by five exposures in I-band and an additional sequence in \nR-band during morning twilight.  All exposures except for the first were \nof 180 seconds duration.\n\nThe afterglow is marginally detected in individual frames and \nwell-detected in a combined stack.  Calibrating relative to five nearby \nSDSS standard stars transformed to R-band using the transformation \nequation of Lupton (2005), the estimated magnitude of the afterglow in \nthe first R-band stack is:\n\nR = 20.91 +/- 0.13 mag  (t_mid = 15.17 hr)\n\nAdditional follow-up is planned if weather permits.",
  "circularId": 10058,
  "createdOn": 1256135071000,
  "email": "dperley@astro.berkeley.edu",
  "subject": "GRB 091020: Lick observations",
  "submitter": "Daniel Perley at U.C. Berkeley  <dperley@astro.berkeley.edu>",
  "eventId": "GRB 091020"
}