TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3252 SUBJECT: GRB 050412 : XingLong optical observation DATE: 05/04/12 18:32:27 GMT FROM: Yuji Urata at RIKEN Y. Qiu, C.L Lu (BAO), Y.Q. Lou(THCA), K.Y. Huang, W.H. Ip(NCU), Y. Urata (RIKEN) on EAFON report " We have observed the XRT error region of GRB 050412 (Tamburelli et al. GCN 3241) using 0.8-m telescope at XingLong Observatory, China. Eight R-band images with each 300 exposure times are taken from 15.93 UT to 16.55 UT (~ 10.20 hrs to 10.82 hrs after the burst). Coadding the eight images yields the 3-sigma limiting magnitude of R~20, which was calibrated relative to USNO-B1.0 catalog. No new source was detected in our images. There is no optical emission from the optical candidate reported by Fox et al. (GCCN 3244) down to the limiting magnitude." This message may be cited.