GSC 03320-02175 , the SIMBAD biblio

We present the results from a photometric monitoring program of 15 open cluster stars and one weak-lined T Tauri star during late-1993/early-1994. Several slow rotators which are members of the Alpha Persei, Pleiades, and Hyades open clusters have been monitored and period estimates derived. Using all available Pleides stars with photometric-periods together with current X-ray vlux measurements, we illustrate the X-ray activity/ortation relation among Pleiades late-G/K dwarfs. The data show a clear break in the rotation-activity relation around P ∼6-7 days–in general accordance with previous results using more heterogeneous samples of G/K stars.