TITLE:   GCN CIRCULAR
NUMBER:  14879
SUBJECT: GRB 130612A: P60 Observations
DATE:    13/06/12 04:56:01 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko@srl.caltech.edu>

S. B. Cenko (NASA/GSFC) and D. A. Perley report on behalf of a larger
collaboration:

We have imaged the field of the Swift GRB 130612A (Racusin et al., GCN
14874) with the robotic Palomar 60 inch telescope.  Observations consist
of individual 120 s frames in the g', r', i', and z' filters beginning at
4:20 UT on 2013 June 12 (58 minutes after the Swift trigger).  The
optical afterglow is detected in individual frames in all four
filters.  Using several nearby point sources from the USNO-B1 catalog for
reference, we measure a magnitude of R = 20.8 at this time.