GCN Circular 14393
M. Im (CEOU/SNU), H.-I. Sung(KASI), and Y. Urata (NCU) on behalf of EAFON We observed the field of GRB 130418A (Pasquale et al., GCN 14377) in R, I, and z filters using the 1-m telescope at Mt. Lemmon observatory in Arizona, US. The observation started at 2013-04-19 03:40 UT, or about 8.6 hours after the BAT alert, and continued for about 45 min. We clearly identify the fading afterglow in R- and I-band, at the location reported earlier (Gorosabel et al. GCN 14378; Quadri et al. GCN 14379; de Ugarte Postigo et al. GCN14380; D'Avanzo et al. GCN 14381; Klotz et al. GCN14382; Kuin et al. GCN14384; Tello et al. GCN 14385; Nardini et al. GCN 14386; Perley et al. GCN 14387; Butler et al. GCN 14388; Covino et al. GCN 14389; Kruehler et al. GCN 14390). On the other hand, the detection in z-band is marginal. Preliminary magnitudes of the afterglow, calibrated against a USNO B-1 star at RA=140.047350 and Dec=+13.655828 are given below: T(mid, UT) Mag 04-19 03:58:26 R=18.95 +- 0.07 04-19 04:04:16 I=18.18 +- 0.08 We thank the LOAO operator, Jae-Hyuk Yoon for performing the observation.