Determining Rotational Periods with Relative Photometry: V836 Tauri & BP Tauri

Rotational periods for the T Tauri stars V836 Tau and BP Tau were determined using relative photometry in the B, V, and R filters. A rotational period of 7.0 days for V836 Tau was found and is consistent with other published periods. This variation in flux is likely caused by a combination of hot and cool spots on the star's surface. Initial analysis of one week's worth of data for the young star BP Tau revealed a rotational period of approximately 5.6 days; with the inclusion of all our data sets taken over 4 years we will obtain a more robust result. This research is part of a larger program with the goal of searching for exoplanets around stars in the Taurus-Auriga association. By comparing photometric rotation periods with radial velocity periods, variability caused by exoplanets rather than star spots can be identified. This research was supported by NSF grant number AST-1004107.