GCN Circular 12444
S. B. Cenko (UC Berkeley) reports on behalf of a larger collaboration: We have imaged the field of GRB111016A (Mangano et al., GCN 12439) with the robotic Palomar 60 inch telescope. Observations began at 11:30 UT on 2011 October 17 (~ 16.9 hours after the initial Swift trigger) and were obtained in the Sloan r', i', and z' filters. Inside the revised localization of the X-ray afterglow (Evans et al., GCN 12441) we marginally detect a source in the i' filter with coordinates: RA: 10:15:20.23; Dec: +27:27:44.0 (J2000.0) Compared with nearby point sources from the Sloan Digital Sky Survey, we measure a magnitude of i' ~ 22.1 +/- 0.3 mag at this time. No significant emission is detected at this location in the r' filter to r' > 21.9 mag. Given the modest significance of the detection in only a single filter, we encourage further observations to confirm if this possible source is indeed the afterglow of GRB111016A.