Radial velocity jitter in stars from the California and Carnegie Planet Search at Keck Observatory

I present an empirical model for predicting a star's radial velocity jitter from its color, B - V activity level, and absolute magnitude. This model is based on observations of similar to 450 well-observed stars from Keck Observatory for the California and Carnegie Planet Search Program. The model includes noise from both astrophysical sources and systematic errors, and describes jitter as generally increasing with a star's activity and height above the main sequence.