GCN Circular 20012
E. Mazaeva (IKI), A. Pozanenko (IKI), B. Hafizov (UBAI), A. Volnova (IKI), O. Burhonov (UBAI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 161004A (Evans et al., GCN 19979) with AZT-22 telescope of Maidanak observatory equipped with SNUCAM in R filter starting on Oct. 04 (UT) 14:25:10. We clearly detected optical afterglow (Evans et al., GCN 19979; Breeveld et al., GCN 19984; Mazaeva et al., GRB 20011). Preliminary photometry of the afterglow in a combined image is following Date UT start t-T0 Filter Exp. OT Err. UL (mid, days) (s) 2016-10-04 14:25:10 0.06981 R 15*120 22.0 0.15 22.7 Photometry is based on nearby SDSS-DR9 stars used in GCN 19980.