TITLE:   GCN CIRCULAR
NUMBER:  34428
SUBJECT: GRB 230812B: further SAO RAS optical observations
DATE:    23/08/15 00:02:33 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

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

We observed the field of GRB 230812B (Lesage et al., GCN 34387;
Scotton et al., GCN 34392; Page, GCN 34394; Zheng & Filippenko, GCN
34395; Lipunov et al., GCN 34396; Salgundi et al., GCN 34397; Ackley
et al., GCN 34398; Xiong et al., GCN 34401; Casentini et al., GCN
34002; Frederiks et al., GCN 34403; Mao et al., GCN 34404; Odeh et
al., GCN 34405; Moskvitin & Spiridonova GCN 34406; Leonini et al. GCN
34408; de Ugarte Postigo et al. GCN 34409; de Ugarte Postigo et al.
GCN 34410; Belkin et al. GCN 34412; Ruocco et al. GCN 34413; Frederiks
et al. GCN 34414; Ruocco et al. GCN 34415; Shrestha et al. GCN 34416;
Quadri et al. GCN 34417; Adami et al. GCN 34418; Moretti et al. GCN
34419; Kumar et al. GCN 34420; Belkin et al. GCN 34421 & GCN 34423;
Pyshna et al., GCN 34425) with the 1-m telescope of SAO RAS Zeiss-1000
equipped with the CCD photometer. We obtained 5 x 300 sec. images in
Rc band on August 14, 19:51:04--20:21:03 UT

The OT is clearly detected in our stacked frame with the brightness of
R = 21.20 +/- 0.09 (t_mid - t0 = 2.0471 days).

This preliminary photometry is based on the nearby SDSS stars;
magnitudes are converted using Lupton (2005) equations.