GCN Circular 26018
V. Kim (AFIF, Pulkovo Observatory) A. Pozanenko (IKI), M. Krugov (AFIF), I. Reva (AFIF), E. Mazaeva (IKI), A. Volnova (IKI) report on behalf of larger GRB IKI FuN collaboration: We observed the field of the GRB 191016A (Gropp al., GCN 26008) with AZT-20 telescope of Assy-Turgen observatory (MPC observatory code 217) starting on Oct. 16 (UT) 14:58:49 in r'-filter. We clearly detect the optical afterglow (Watson al., GCN 26010; Zheng al., GCN 26011; Watson al., GCN 26015; Hu et al., GCN 26017). Preliminary photometry of the afterglow is following. Date UT start t-T0 Filter Exp. OT Err. (mid, days) (s) 2019-10-16 14:58:49 0.48336 r' 120*30 20.6 0.15 The photometry is based on the nearby USNO-B1 stars and BRI transformations to r'. The photometry in agreement with non detection of the optical afterglow by Jelinek et al. (GRB 26013).