{
  "bibcode": "2015GCN.18029....1C",
  "body": "S. B. Cenko (NASA/GSFC) and D. A. Perley (DARK) report on behalf of a larger collaboration:\n\nWe have imaged the location of the X-ray afterglow of GRB 150716A (Kocevski et al., GCN 18027) with the automated Palomar 60 inch telescope.  Observations were obtained in the r, i, and z filters beginning at 07:11 UT (~ 4 minutes after the Swift trigger time) and ending at 8:18 UT.  Within the XRT error circle, we detect a large number of sources, one of which shows marginal evidence for fading:\n\n  RA: 18:33:57.13\n  Dec: -12:58:46.3\n\nBy comparison with the nearby USNO-B1 catalog star 0770-0591035 (I2 magnitude = 17.66), we measure the following magnitudes for this source:\n\nUT          Magnitude\n----------------------------------\n07:11      21.48 +/- 0.22\n08:17      > 22.15 \n\nThe source reported by RATIR (Watson et al, GCN 18028) is clearly detected in our images, but a) does not appear to fade, and b) is outside the revised XRT error circle.\n\nWe thank Alan Watson and Nat Butler for sharing the RATIR images with us.",
  "circularId": 18029,
  "createdOn": 1437080556000,
  "email": "brad.cenko@nasa.gov",
  "subject": "GRB 150716A: P60 Candidate Optical Afterglow",
  "submitter": "S. Bradley Cenko at NASA/GSFC  <brad.cenko@nasa.gov>",
  "eventId": "GRB 150716A"
}