{
  "bibcode": "2012GCN.14048....1F",
  "body": "W. Fong (Harvard), D. Fox (PSU), E. Berger and R. Chornock (Harvard) report:\n\n\"We observed the location of GRB 121209A (Maselli et al., GCN14045) with\nthe Gemini Multi-Object Spectrograph (GMOS) mounted on the Gemini-South 8-meter\ntelescope starting on 2012 Dec 10.028 UT (2.68 hr after the BAT trigger).\nWe obtained 60-sec in each of the r- and i-bands in 0.75\" seeing. We do not\ndetect any optical source within the XRT position reported in GCN 14045,\nnor within the latest reported position (\nhttp://www.swift.ac.uk/xrt_unenh_positions/00540964/). Calibrated to stars\nin the SDSS DR8 field, we place 3-sigma limits of r > 22.6 mag and i > 23.0\nmag on the optical afterglow of GRB 121209A at 2.7 hr after the burst\n(uncorrected for Galactic extinction in the direction of the burst).\n\nWe thank the Gemini staff for their assistance with these observations.\"",
  "circularId": 14048,
  "createdOn": 1355111412000,
  "email": "wfong@cfa.harvard.edu",
  "subject": "GRB 121209A: Gemini-South imaging",
  "submitter": "Wen-fai Fong at CFA  <wfong@cfa.harvard.edu>",
  "eventId": "GRB 121209A"
}