Saskia Hekker, Elisabeth Guggenberger, Nathalie Themessl

Over 35 years ago, it was proposed that there exists diagnostic potential in combining the small and large frequency separations for solar-like oscillators. Since then, we have been spoilt with a plethora long-timeseries photometric light curves from which individual stochastic oscillation modes can be extracted. These light curves allow the separations to be determined en masse and in power spectra with relatively low signal-to-noise ratios. The small-frequency separation in low-mass main-sequence stars and in subgiants is sensitive to the molecular weight gradient in the inner regions whilst the large-frequency separation is indicative of the mean density of the star. We investigate how accurately these parameters must be determined in order to place constraints on stellar parameters such as mass and age. We discuss some difficulties associated with calculating the necessary large grids of models (with different input physics) as well as the degeneracy that exists in later evolutionary phases.