TITLE: GCN CIRCULAR NUMBER: 3207 SUBJECT: GRB 050408: Optical limit at 20 min after the burst DATE: 05/04/09 12:27:01 GMT FROM: Yuji Urata at RIKEN T. Mizuno, Y. Arai, H. Yamagishi (Tokyo Gakugei Univ.), T. Soyano (Kiso observatory), Y. Urata, T. Tamagawa(RIKEN), K.Y. Huang(NCU) on behalf of EAFON report, " We have imaged the entire error region of GRB 050408 (GCN3189) with 1.05m Schmidt telescope at Kiso observatory, Japan in R band. Utilizing HETE-2 GCN alert, the observation was started at 16:42 UT (20 min after the burst) and lasted to 1 hour. There is no optical emission from the optical afterglow (GCN 3192, GCN 3196) down to a limiting magnitude of R=19.1 as estimated using USNO B1.0 catalog. This message may be cited."