TITLE: GCN CIRCULAR NUMBER: 4239 SUBJECT: Early RAPTOR measurements of GRB 051109a - the movie. DATE: 05/11/10 00:37:54 GMT FROM: Przemyslaw R. Wozniak at LANL P.R. Wozniak, W.T. Vestrand, J. Wren, R. White, S. Evans on behalf of the RAPTOR team report: Starting at 01:12:54.42 UT on November 9, 33.9 seconds after the Swift BAT trigger, the Raptor-S robotic telescope at Los Alamos National Laboratory responded to Swift trigger 163136 (Tagliaferri et al., GCN 4213). The automated response was composed of a series of ten 5-second duration exposures followed by 20 10-second exposures and finally by 183 30-second exposures. The unfiltered images show an optical transient at the position identifed by Rykoff et al. (GCN 4211) that fades from magnitude R ~15.1 to ~17.5 over the course of 20 minutes. The unfiltered magnitudes were transformed to the R2 magnitude scale of the USNO B1.0 catalog. Short animations derived from the RAPTOR images can be viewed at: EPISODE I: "The First Four Minutes" http://www.raptor.lanl.gov/images/GRB051109a/grb051109a_early_movie.gif EPISODE II: "The Next Half Hour" http://www.raptor.lanl.gov/images/GRB051109a/grb051109a_late_movie.gif