Red Giant Seismology: Seismic Signatures of Convective Overshoot

Most red giant models do not reproduce the position of the observed luminosity bump, a diagnostic of the maximum extension of the convective envelope during the first-dredge up. Global seismic parameters, the large frequency separation and frequency of maximum oscillation, show that overshoot below the convective envelope helps match red giant model luminosity bump positions to observed bump positions. The global seismic properties, however, cannot be used to probe envelope overshoot in a star-by-star manner. The long time series of Kepler and the TESS continuous viewing zones (CVZ) allow us to determine the individual mode frequencies of many red giants and these individual modes allow us to probe the internal structure of the stars. Red giant mixed modes (modes that are p-like (i.e., acoustic modes) at the surface and g-like (i.e., gravity modes) in the core) contain important information about the interior structure of the star. We present the results of a theoretical study to investigate the seismic signature of convective overshoot in red giants. Our intention is to use these signatures to determine the amount of overshoot needed to model observed frequencies in red giants that have high quality seismic data.