Observational $\Delta\nu$-$\bar\rho$ relation for $\delta$ Sct stars using eclipsing binaries and space photometry

TL;DR

This study establishes an observational relation between mean stellar density and oscillation frequency patterns in delta Scuti stars, derived from eclipsing binary data and space photometry, aiding their precise characterization.

Contribution

The paper introduces a new density-frequency scaling relation for delta Scuti stars, independent of rotation, based on eclipsing binary observations and space photometry.

Findings

Derived a density-frequency relation for delta Scuti stars.

Showed the relation is independent of stellar rotation.

Validated the frequency pattern as a new observable.

Abstract

Delta Scuti ($\delta$ Sct) stars are intermediate-mass pulsators, whose intrinsic oscillations have been studied for decades. However, modelling their pulsations remains a real theoretical challenge, thereby even hampering the precise determination of global stellar parameters. In this work, we used space photometry observations of eclipsing binaries with a $\delta$ Sct component to obtain reliable physical parameters and oscillation frequencies. Using that information, we derived an observational scaling relation between the stellar mean density and a frequency pattern in the oscillation spectrum. This pattern is analogous to the solar-like large separation but in the low order regime. We also show that this relation is independent of the rotation rate. These findings open the possibility of accurately characterizing this type of pulsator and validate the frequency pattern as a new observable for $\delta$ Sct stars.