TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3335 SUBJECT: GRB 050502a : R band observation at Lulin observatory DATE: 05/05/02 16:49:12 GMT FROM: Yuji Urata at RIKEN K. Sanchawala, W.L. Wu, K.Y. Huang, W.H. Ip(NCU), Y. Qiu, W. Zhou (BAO), Y.Q. Lou (THCA), Y. Urata (RIKEN), on behalf of EAFON report: " We have observed the position of GRB 050502a optical afterglow (Yost et al. GCN 3322) using 1-m telescope at Lulin Observatory, Taiwan. Under unstable weather condition, single R band image was taken at 15.59 UT (~ 13.37 hours after the burst). The limiting magnitude is R~ 21 compared with USNO-B1.0 stars. No source was detected down to the limiting magnitude at the position. This message may be cited."