TITLE:   GCN CIRCULAR
NUMBER:  34456
SUBJECT: GRB 230816A: SAO RAS optical observations
DATE:    23/08/16 19:26:01 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 the GRB 230816A (Siegelet al., GCN 34450)
with the 1-m telescope of SAO RAS Zeiss-1000 equipped with the CCD
photometer. We obtained 8 x 300 sec. images in Rc band on August 16,
17:45:41 -- 18:35:29 UT.

The OT (Jiang et al., GCN 34453) is clearly detected in our stacked
frame with the coordinates
R.A. (J2000) = 21:53:46.9,
Decl.(J2000) = +37:51:16.7 (+/- 0".5)
and the brightness of R = 21.0 +/- 0.1 (t_mid - t0 = 2.030h = 0.0846d).

This preliminary photometry is based on nearby USNO-B1 stars (R2 mag),
the magnitude is not corrected for MW extinction.