TITLE: GCN CIRCULAR NUMBER: 14464 SUBJECT: GRB 130427A: Optical Observations DATE: 13/04/27 15:40:25 GMT FROM: Myungshin Im at Seoul Nat U M. Im (CEOU/SNU) on behalf of a larger collaboration We observed GRB 130427A (Maselli et al., GCN 14448) in BVRI filters using T30 telescope (0.5m) of the iTelescope network (AAO, Australia), and also are conducting follow-up imaging observations using facilities in Korea. The T30 observation started at about 4 hours after the BAT alert, and other observations starting at a similar epoch. We clearly identify the fading afterglow in T30 images, at the location reported earlier (Elenin et al. GCN 14450). Preliminary BRI magnitudes of the afterglow in one of the epochs, calibrated against a USNO B-1 star in the vicinity of the afterglow, are given below: T(mid, UT) Mag 04-27 11:42:56 I=14.86 +- 0.12 04-27 11:45:29 R=15.60 +- 0.10 04-27 11:50:29 B=16.10 +- 0.15 Follow-up observations are still ongoing.