TITLE: GCN CIRCULAR NUMBER: 13031 SUBJECT: GRB 120308A : LOAO optical observation DATE: 12/03/10 15:26:15 GMT FROM: Minsung Jang at Seoul National U Jang, M., Im, M. (SNU), & Urata, Y. (NCU) We observed GRB 120308A (Baumgartner et al., GCN 13017) in R, I-bands with a 1 m telescope at Mt. Lemmon, Arizona, U.S. The obsevation started at 10:51:23 2012-03-08 UT, ~ 4.6 hours after the burst alert. We alternatively took 6 frames for each filter with the exposure time, 300s. We found a optical afterglow candidate in the stacked I image with a preliminary magnitude, I ~ 18.7 +/- 0.12 mag at mid-point time, 17274 sec after the burst alert on the enhanced XRT position (Evans et al., GCN13023). However, no afterglow candidate was found in the stacked R image. We thank the LOAO operator, J. Yoon for this observation.