Magnetic activity evol. of solar-like stars. I.

While ages are usually computed from stellar evolution models, relations linking ages to other stellar properties, such as rotation and magnetic activity, have been investigated. With the large catalog of 55232 rotation periods, Prot, and photometric magnetic activity index, Sph from Kepler data, we have the opportunity to look for such magneto-gyro-chronology relations.

Stellar ages are obtained with two stellar evolution codes that include treatment of angular momentum evolution, hence using Prot as input in addition to classical atmospheric parameters. We explore two different ways of predicting stellar ages on three subsamples with spectroscopic observations: solar analogs, late-F and G dwarfs, and K dwarfs. We first perform a Bayesian analysis to derive relations between Sph and ages between 1 and 5Gyr, and other stellar properties.