TITLE:   GCN CIRCULAR
NUMBER:  18294
SUBJECT: GRB150911A: P60 Observations
DATE:    15/09/12 15:24:56 GMT
FROM:    S. Bradley Cenko at NASA/GSFC  <brad.cenko@nasa.gov>

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

We observed the location of GRB150911A (Starling et al., GCN 18280) with the robotic Palomar 60-inch telescope.  Observations were obtained in the r', i', and z' filters beginning at 09:03 UT on 2015 Sep 12 (dt ~ 14.4 hours after the Swift trigger).  In stacked images we do not detect any sources within the enhanced XRT error circle (Goad et al., GCN 18283) in any filter.  Using comparison point sources from the USNO-B1 catalog for reference, we calculate a limiting magnitude of R > 22.5 in a stacked image at a median time of 09:46 UT on 2015 Sep 12.