GRB 210610A: CrAO/ZTSH optical observations

We observed the GRB 210610A (Page et al., GCN 30170) with ZTSH 2.6m telescope of CrAO observatory starting on June 11 (UT) 19:46:53. The optical afterglow first reported by UVOT (Page et al., GCN 30170) is clearly detected in each of a single image of 120 exposure in R filter. Preliminary photometry of the afterglow in the first image is following Date UT start t-T0 Filter Exp. OT err (mid, days) (s) 2021-06-11 19:46:53 0.99683 R 1*120 19.50 0.12 The photometry is based on several nearby USNO-B1.0 (R2) stars USNO-B1.0 id USNO_B10-1043-00282648 USNO_B10-1043-00282621