TITLE: GCN CIRCULAR NUMBER: 14457 SUBJECT: GRB 130427A: iTelescope T11 optical observations DATE: 13/04/27 12:26:03 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 detected GRB 130427A optical afterglow at iTelescope observatory T11 (Mayhill, New Mexico) 0.50-m/6.8 astrograph and FLI ProLine PL11002M CCD. Three unfiltered and three photometric V filter images with 120 sec exposure time were made. The afterglow was detected at following position RA 11:32:32.83 and DEC +27:41:56.4 The following magnitudes were obtained from the observations using NOMAD1 1176-0248446 (R=13.520, V=13.120) as the comparison: Tmid(sec)+T0 Filter Exp. time Mag Mag err. 4597 unfiltered 120 15.02CR 0.04 4743 unfiltered 120 15.09CR 0.05 4887 unfiltered 120 15.11CR 0.05 5438 V 120 14.89V 0.04 5582 V 120 14.89V 0.04 5726 V 120 14.86V 0.04