TITLE: GCN CIRCULAR NUMBER: 6977 SUBJECT: GRB071010b: optical observation DATE: 07/10/22 18:22:00 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the optical afterglow (Oksanen GCN 6873, Kann et al. GCN 6884) of GRB071010b (Markwardt et al., GCN 6871) in R-band on Oct.19 between (UT) 01:39:50 - 02:54:14 with Zeiss-1000 (Simeiz) telescope of CrAO observatory. Based on USNO-A2.0 star RA (J2000) = 10 01 59.67, Dec. (J2000) = +45 46 12.80, R=18.30 we estimated brightness of the optical afterglow: T0+, Exposure, R_mag, err (mid time) 8.230 d 58x60 s 21.9 +0.37 -0.27 The message may be cited.