{
  "bibcode": "2013GCN.15625....1C",
  "body": "S. B. Cenko (NASA/GSFC) and D. A. Perley (Caltech) report on behalf of a\nlarger collaboration:\n\nWe observed the location of the optical afterglow (Zheng et al., GCN\n15617) of the Swift GRB 131227A (Oates et al., GCN 15616) with the robotic\nPalomar 60 inch telescope.  Observations were obtained in the r', i', and\nz' filters beginning at 05:59 UT on 2013 Dec 27 (~ 1.24 hours after the\nSwift trigger time).  We do not detect any sources at the location of the\nKAIT optical afterglow.  Using nearby point sources from the USNO-B1\ncatalog for reference, we calculate an upper limit of r > 21.0 mag at a\nmean epoch of 1.50 hr after the Swift trigger.",
  "circularId": 15625,
  "createdOn": 1388171101000,
  "email": "cenko@srl.caltech.edu",
  "subject": "GRB 131227A: P60 Limits",
  "submitter": "S. Bradley Cenko at Caltech  <cenko@srl.caltech.edu>",
  "eventId": "GRB 131227A"
}