<i>Y</i> ² Isochrones with an Improved Core Overshoot Treatment

Convective core overshoot affects stellar evolution rates and the dating of stellar populations. In this paper, we provide a patch to the Y 2 isochrones with an improved treatment of convective core overshoot. The new tracks cover the transition mass range from no convective core to a fully developed convective core. We compare the improved isochrones to CMDs of a few well observed open star clusters in the Galaxy and the Large Magellanic Cloud. Finally we discuss future prospects for improving the treatment of core overshoot with the help of asteroseismology. Subject headings: convection — stars: interiors — stars: evolution