GRB 210207B: AbAO optical upper limit

We observed the field of GRB 210207B (Lien et al., GCN 29420) with AS-32 telescope of Abastumani observatory (AbAO) in R-filter starting on 2021-02-08 (UT) 02:14:17. The optical afterglow (Lien et al., GCN 29420; Kumar et al., GCN 29421) is not detected in stacked image. Date UT start t-T0 Filter Exp. OT Err. UL(3sigma) (mid, days) (s) 2021-02-08 02:14:17 0.19837 R 47*60 n/d n/d 18.7 The photometry is based on nearby USNO-B1.0 stars USNO-B1.0_id R2 1436-0267956 15.29 1436-0268040 15.52 The non-detection of the afterglow implies a jet break somewhere before of our observations, or the source of the GRB 210207B is highly redshifted.