TITLE: GCN CIRCULAR NUMBER: 26964 SUBJECT: GRB 200131A: CDK700 optical observations DATE: 20/02/02 21:01:36 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Pozanenko (IKI), V. Kim (AFIF, Pulkovo Observatory), I. Reva (AFIF), M. Krugov (AFIF), E. Mazaeva (IKI), A. Volnova (IKI) report on behalf of larger GRB IKI FuN collaboration: We observed the field of the GRB 200131A (Sbarufatti al., GCN 26953) with CDK700 (0.7m) telescope of Assy-Turgen observatory starting on Feb. 01 (UT) 14:58:49 in R-filter. We marginally detect the optical afterglow (Sbarufatti al., GCN 26953; Lipunov al., GCN 26954; Butler al., GCN 26957; Strausbaugh al., GCN 26959; Kuin al., GCN 26962). Preliminary photometry of the afterglow is following. Date UT start t-T0 Filter Exp. OT Err. UL(3sigma) (mid, days) (s) 2019-02-01 14:58:49 0.76733 R 14*360 21.4 0.3 21.5 The photometry is based on nearby USNO-B1.0 stars (R2 magnitudes).