TITLE: GCN CIRCULAR NUMBER: 14410 SUBJECT: GRB 130420A: T21 optical observations DATE: 13/04/20 13:06:20 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 130420A optical afterglow at iTelescope Observatory T21 (Mayhill, New Mexico) 0.43-m/6.8 astrograph and FLI ProLine PL6303E CCD. Two unfiltered images with 600 sec exposure time were made. The afterglow was detected at following position RA 13:04:25.51 and DEC +59:25:27.2. The following magnitudes were obtained from the observations using NOMAD1 1494-0215473 (R=16.220) as the comparison: Tmid(sec)+T0 Filter Exp. time Mag Mag err. Limit 7258 unfiltered 600 19.49CR 0.20 20.60 7885 unfiltered 600 19.61CR 0.24 20.48