GCN Circular 10626
R. Pearson, J. Ward Moody, and C. Pace report for Brigham Young University's (BYUs) ROVOR team: Beginning 9.12 hours after the initial Swift detection of GRB 100418A (GCN 10612), the 16-inch ROVOR telescope observed its optical afterglow. Twenty-eight 2 minute R band exposures were recorded at high airmass (2.48) and subsequently averaged together; a combined frame of 56 minutes was produced. An optical afterglow was located at the position specified by Filgas, Klose, and Greiner (GCN 10617). We report a middle observing time of 06:55:21.474 (9.75 hrs post-burst) and a R band magnitude of 18.2+/-0.2mag. It was calibrated using GSC 00984-01465 located at 17:05:55.02+11:27:55.46 (J2000). Additional follow-up observations are scheduled with ROVOR as well as BYU's 36-inch telescope on West Mountain Observatory, supported by the NSF grant AST-0618209.