TITLE:   GCN CIRCULAR
NUMBER:  34987
SUBJECT: GRB 231110A: SAO RAS optical observations
DATE:    23/11/11 21:59:36 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

A. S. Moskvitin and O. A. Maslennikova (SAO RAS)
report on behalf of the GRB follow-up team.

We observed the field of Swift GRB 231110A (D'Elia et al., GCN #34977)
with the 1-m telescope of SAO RAS equipped with the CCD photometer.
We obtained 8 x 300 sec. images in Rc band on November 10,
22:09:05--22:55:32 UT (t_mid - T0 = 1.21224 hours).

Following the non-detection of OT by MASTER team (Lipunov et al.,
GCN #34978) we also did not detect any significant source within
the probable XRT error circle (Beardmore et al., GCN #34986)
down to the limiting magnitude R_lim = 22.9. We should note
the presence of the first object mentioned by Sun et al. (GCN #34979)
near the XRT error circle. The brightness of this object is
R = 22.50 +/- 0.24.

Preliminary photometry is based on nearby USNO-B1 stars (R2 mag).
Magnitudes are not corrected for MW extinction.