TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3239 SUBJECT: GRB 050412: LCO optical observations DATE: 05/04/12 08:29:43 GMT FROM: Edo Berger at Carnegie Obs Edo Berger (Carnegie Observatories), Nidia Morrell (LCO), Brian Schmidt (RSAA, ANU), Derek Fox (Caltech), and Paul Price (IfA, Hawaii) report on behalf of a larger collaboration: "Starting on 2005, April 12.267 UT (41 min after the burst) we imaged the BAT error circle of GRB 050412 (GCN 3237) with the DuPont 100-inch telescope at LCO in the R-band. Two 10-minute images were obtained. A comparison to DSS reveals no new sources to the limit of the survey (R~20.5 mag). Furthermore, no sources exhibit a clear fading behavior between the two images to a limit of R~20.5 mag and delta-R~0.2 mag."