GCN Circular 18275

A.S.Moskvitin (SAO RAS), V.P.Goranskij (SAI, Moscow State University),
report on behalf of larger GRB follow-up team:

We observed the field of the GRB 150910A (Pagani et al., GCN #18264)
with the Zeiss-1000, 1-meter telescope of SAO RAS (Russia),
equipped with the broadband filters UBVRcIc and EEV 42-40 CCD.
The observations started since 10.85 hours after the trigger.

We obtained sets of 6 x 300-sec. frames in Rc band three times per
September, 10/11 night. The OT (reported by Pagani et al., GCN #18264;
Zheng & Filippenko, GCN #18265; Dichiara et al., GCN #18266;
Kuroda et al., GCN #18267; Xu et al., GCN #18269; McCauley & Pagani,
GCN #18270; Zheng et al., GCN #18273; de Ugarte Postigo et al.,
GCN #18274) is clearly visible even in single frames.
The results of observations are as following.

#   (T_mid-T0),h   exp.,s     R_mag            time, UT
1.  11.035         6 x 300    20.20 +/- 0.05   19:56:03--20:17:48
2.  13.448         6 x 300    20.57 +/- 0.05   22:15:17--22:48:09
3.  15.739         6 x 300    20.78 +/- 0.05   00:32:30--01:05:46

Photometry is based on nearby SDSS stars (their magnitudes
were converted with the Lupon 2005 equations).