TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5021 SUBJECT: GRB 060428b : Kiso R-band limit DATE: 06/04/28 13:16:35 GMT FROM: Yuji Urata at Saitama U M.Abe (ISAS/JAXA), Y. Sarugaku, H.Mito (Tokyo Univ.), Y.L. Qiu, W.K. Zheng (NAOC), K.Y. Huang(NCU), Y. Urata (Saitama Univ.) on behalf of EAFON report: "We have observed the GRB 060428B field (GCN #5017) using Kiso 1.05m telescope. The R and B band observations were started from 2.3 hours after the burst (after end of twilight). The limiting magnitude derived from USNOB1.0 is R=20.7 (SN=3). The candidate (GCN #5019) do not appear brighter than the limiting magnitude. This result indicates that the candidate is afterglow of GRB 060428B. Further analysis is in progress." This message may be cited.