TITLE:   GCN CIRCULAR
NUMBER:  18295
SUBJECT: GRB150910A: P60 Observations
DATE:    15/09/12 16:15:10 GMT
FROM:    Daniel Perley at Caltech  <dperley@astro.caltech.edu>

D. A. Perley (DARK) and S. B. Cenko (NASA/GSFC) report:

We observed the location of GRB 150910A (Pagani et al., GCN 18264) using 
the robotic Palomar 60-inch telescope on two epochs during the night of 
2015-09-11 UT, and an additional epoch during the night of 2015-09-12 
UT.  During each epoch we acquired 3x180s of imaging in each of the g', 
r', and i' filters.

The optical afterglow (Pagani et al.; Zheng and Filippenko, GCN 18265) 
is detected in each observation.  Preliminary photometry relative to 
SDSS yields:

t_start(d)  filt   mag      emag
    0.973    i  =  21.24 +/- 0.12
    0.980    g  =  21.54 +/- 0.06
    0.989    r  =  21.35 +/- 0.08
    1.067    i  =  21.28 +/- 0.07
    1.074    g  =  21.85 +/- 0.06
    1.081    r  =  21.50 +/- 0.06
    2.060    i  =  22.21 +/- 0.17
    2.067    g  =  22.66 +/- 0.14
    2.074    r  =  23.03 +/- 0.26