TITLE: GCN CIRCULAR NUMBER: 14488 SUBJECT: GRB 130427A: Continued iTelescope T21 optical observations DATE: 13/04/28 11:37:46 GMT FROM: Veli-Pekka Hentunen at Taurus Hill Obs,A95 Veli-Pekka Hentunen, Markku Nissinen and Tuomo Salmi (Taurus Hill Observatory, Varkaus, Finland) report: We have continued observing GRB 130427A optical afterglow at iTelescope observatory T21 (Mayhill, New Mexico) 0.43-m/6.8 astrograph and FLI-PL6303E CCD. Two unfiltered, two photometric R filter and two photometric V filter images with 600 sec exposure time were made. The following magnitudes were obtained from the observations using NOMAD1 1176-0248446 (R=13.520, V=13.120) as the comparison: Tmid(h)+T0 Filter Exp. time Mag Mag err. 22.67 V 600 17.73V 0.11 22.85 V 600 17.72V 0.11 23.10 unfiltered 600 18.01CR 0.07 23.27 unfiltered 600 18.22CR 0.09 23.56 R 600 18.18R 0.12 23.74 R 600 18.36R 0.14