TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3787 SUBJECT: GRB050813 (Swift 150139): P60 Observations DATE: 05/08/13 07:51:35 GMT FROM: Derek Fox at CIT Derek B. Fox (Penn State) and S. Bradley Cenko (Caltech) report on behalf of a larger collaboration: "The Robotic 60-inch Telescope at Palomar Observatory (P60) responded automatically to Swift Trigger 150139, recording a series of images beginning at 06:50:30 UT, approximately 6 minutes after the burst. Visual inspection of these images does not reveal any new objects by comparison to the second-generation DSS images (XDSS). Times and approximate limits (calibrated against USNO-B1.0 catalog photometry) for new point sources within the BAT error circle are as follows: Band Exp Epoch Limit ========================================== R 60s 06:51:00 R > 18.3 mag i 60s 06:53:22 I > 17.0 mag R 3x60s 06:58:18 R > 18.9 mag ========================================== Observations will continue as long as the source is visible."