TITLE: GCN CIRCULAR NUMBER: 7378 SUBJECT: GRB080307 BOAO optical afterglow observation - detection of a possible OT DATE: 08/03/08 08:12:01 GMT FROM: Myungshin Im at Seoul Nat U M. Im, I. Lee, Y. Urata, W.K. Zheng, K.Y. Huang, on behalf of EAFON team. We re-analyzed the I-band images taken with the 1.8m telescope of the Bohyunsan Optical Astronomy Observatory, Korea. The I-band observation started at 76.1 min after the burst (Holland et al. #7362), and continued for 2100 secs. Our reanalysis of the stacked image show the detection of a possible optial transient within the error circle of the XRT position (Goad et al. #7366), and the reported Gemini-N i-band position (Tanvir et al.7369). The brightness of the OT, calibrated against USNO-B1 star at (09:06:31.6,+35:08,06.4), is I ~ 21.9 +- 0.3 mag with the error arising mostly from the uncertainty associated with the subtraction of the fringe pattern. Further deeper imaging is encouraged. We thank J. Seo and Yeon-Bom Jeon for their assistance with the BOAO observation. This message may be cited.