An attempt to calibrate core overshooting using the seismic properties of low-mass stars

Abstract

The sizes of stellar convective cores remain uncertain because of our poor understanding of the interface between convective and radiative zones. The very high precision of the seismic data provided by the CoRoT and Kepler space missions offers a great opportunity to search for the signature of convective cores in main-sequence stars. We here validate the seismic diagnostic based on the r010 ratios, which has been proposed to probe the size of convective cores, and we use it on a sample of 24 specially chosen Kepler targets. We thus constrain the extension of the core in 14 targets and find a tendency of the core extension to increase with stellar mass in this mass range. These results will be presented in more detail in a paper in preparation.