TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2919 SUBJECT: GRB041228: ROTSE-III Optical Observations DATE: 04/12/28 20:03:23 GMT FROM: Eli Rykoff at U of Michigan/ROTSE E. Rykoff (U. Michigan) reports on behalf of the ROTSE collaboration: ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, responded to Swift GRB041228 (GCN #2918). An automatic response was initiated during early twilight hours. The first usable image was taken at 28 Dec 18:38:44 UT, 7.8 hours after the burst. We took 50 60-s exposures before the burst position dropped below our minimum observing elevation. The unfiltered images were calibrated relative to USNO A2.0. Individual images have limiting magnitudes ranging from 17-18 as the sky darkened. Comparison to DSS (second epoch) reveals no new sources within the 3-sigma error circle to a limiting magnitude of 18.8 for stacks of 10 images taken 8.4 hours after the burst.