Theoretical properties of regularities in the oscillation spectra of A-F main-sequence stars

We study the theoretical properties of the regular spacings found in the oscillation spectra of delta Scuti stars. A linear relation between the large separation and the mean density is predicted to be found in the low-frequency domain (i.e. radial orders spanning from 1 to 8, approximately) of the main-sequence delta Scuti stars' oscillation spectrum. This implies an independent direct measure of the average density of delta Scuti stars, analogous to that of the Sun, and places tight constraints on the mode identification and hence on the stellar internal structure and dynamics, and allows a determination the radii of planets orbiting around delta Scuti stars with unprecedented precision. This opens the way for studying the evolution of regular patterns in pulsating stars, and its relation to stellar structure and evolution.