I. Bikmaev, R. Zhuchkov, R. Gumerov, A. Nemtinov, N. Sakhibullin
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),
Z. Eker, I. Khamitov (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.)
The field of GRB 110312A (Oates et al., GCN 11782) was observed with
Russian-Turkish 1.5-m telescope (RTT150,Bakirlitepe, TUBITAK National
Observatory, Turkey) in March 12, 2011, during UT 20:00 - 21:40,
i.e. starting approximately 2 hours after the burst.
We obtained serie of 16 exposures by 300 sec each in Rc filter.
We found no optical source within the 1.7" enhanced XRT error circle
(Osborne et al.; GCN 11784) in co-added image with frame limit of
Rc ~ 23.5 mag