The photometric variability of solar-type stars. I. Preliminary results for the Pleiades, Hyades and the Malmquist field.

The young main sequence stars in the Pleiades and Hyades clusters, and old disk stars in the Malmquist Field near the north galactic pole, have been observed by precision photometry in order to determine the prevalance of variability among solar type stars. Significant variations have been found in at least five, and possibly ten, of 44 Hyades stars, and possibly one of the 41 stars in the Malmquist Field, all of which are of spectral type F8 V-K2 V.