The Evolution of the Angular Momentum Distribution during Star Formation

We have estimated the ages of eight late-type Vega-like stars by using standard age-dating methods for single late-type stars, e.g., location on the color-magnitude diagram, Li lambda6708 absorption, Ca ii H and K emission, X-ray luminosity, and stellar kinematic population. With the exception of the very unusual pre-main-sequence star system HD 98800, all the late-type Vega-like stars are the same age as the Hyades cluster (600-800 Myr) or older.