TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3120 SUBJECT: GRB 050319 : Confirmation of optical afterglow decay DATE: 05/03/19 16:42:37 GMT FROM: Yuji Urata at RIKEN GRB 050319 : Confirmation of optical afterglow decay T. Yoshioka (Naogya Univ.), C.W. Chen (NCU), S.Nishiura (Tokyo Gakugei Univ.), M. Isogai (Tokyo Univ.), T. Soyano(Tokyo Univ.), W.P. Chen (NCU) Y. Urata, T. Tamagawa (RIKEN), K.Y. Huang, W.H. Ip (NCU), Y. Qiu (BAO) and Y.Q. Lou(THCA) on behalf of the East Asian collaboration report: " We have observed the afterglow candidate of GRB 050319 (Rykoff et al. # 3116, Krimm et al. # 3117) using Kiso 1.05-m and Lulin 1-m telescopes starting at 2005 Mar. 19, 10:45 UTC (after end of twilight). We have imaged the optical candidate (Rykoff et al. # 3116) clearly in BVRI bands. Based on our preliminary photometry for R-band images, we have confirmed the decay of the optical candidate. Observation time and magnitudes are: Filter Exposure UT Mag. site R 300s 10:45 19.5 Kiso R 300s 11:28 19.5 Lulin R 300s 13:29 20.0 Kiso Further observations are in progress, this message may be cite."