TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5548 SUBJECT: GRB 060904B: Kiso Optical observation DATE: 06/09/08 11:55:05 GMT FROM: Yuji Urata at Saitama U T. Soyano, H. Mito (Tokyo Univ), and Y. Urata (Saitama Univ) on behalf of EAFON report: " We have made R-band follow-up observation of GRB 060904B afterglow (Grup et al.; Rykoff et al; Fugazza et al.) using Kiso 1.05m Schmidt telescope. The observation was started at 15:27 UT September 4, 2006 and lasted till 19:30. The preliminary analysis shows the optical afterglow with 21.4+/-0.2 mag at 15.72 hours after the burst. Further analysis is in progress. This message may be sited."