TITLE: GCN CIRCULAR NUMBER: 14582 SUBJECT: GRB 130427A: optical observations in CrAO DATE: 13/05/05 22:29:40 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev (CrAO), K.Antoniuk (CrAO), D. Shakhovskoy (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We continue observation of the Swift GRB 130427A (Maselli et al., GCN 14448) with AZT-11 telescope of CrAO observatory. Preliminary photometry the optical afterglow of GRB 130427A (Maselli et al., GCN 14448, Elenin et al. GCN 14450, Perley GCN 14451) is following T_start (UT) T0+ Filter Exp. OT mid,days s mag 2013-05-02T19:34:45.35 5.5618 R 6120 19.75 +/- 0.15 2013-05-03T20:41:27.17 6.5581 R 3600 20.30 +/- 0.25 2013-05-04T18:26:22.25 7.4747 R 5400 20.20 +/- 0.18 Photometry is based on SDSS star SDSS id B eB V eV R eR I eI J113220,11+274133,5 17,421 0,020 16,911 0,020 16,561 0,015 16,124 0,016