GCN Circular 30492
M. Jelinek, J. Strobl, R. Hudec, C. Polasek (ASU CAS Ondrejov) report: We observed the position of the bright GRB 210722A (D'Avanzo et al., GCN 30475; Page et a., GCN 30483; Barthelmy et al. GCN 30489; and Wood, GCN 30490) with the D50 telescope of the Astronomical Institute Ondrejov, near Prague, Czech Republic. We performed a set of 35x 60s exposures in SDSS-i' filter on July 24 from 1:20 to 2:01 UT. The optical afterglow (Zhu et al., GCN 30476; Pankov et al., GCN 30478 & 30488; Kumar et al., GCN 30481; Butler et al., GCN 30484; and Thoene et al., GCN 30487) is weakly detected in the overall combined image with the exposure mean time 28.9h after trigger. The Atlas-calibrated magnitude of the object is i' = 19.8 +/- 0.4.