Discovery of tidally-perturbed pulsations in the eclipsing binary U Gru: a pioneering system for tidal asteroseismology

TL;DR

This paper reports the discovery of tidally-perturbed pulsations in the eclipsing binary U Gru, demonstrating how tidal asteroseismology can reveal the impact of binary interactions on stellar interior physics, especially for early-type stars.

Contribution

It introduces the first detailed analysis of tidally-perturbed pulsations in an eclipsing binary, showcasing the potential of tidal asteroseismology for studying stellar interiors.

Findings

Detection of free heat-driven pressure modes in U Gru

Identification of tidally-perturbed pressure modes

Demonstration of tidal asteroseismology's potential for binary systems

Abstract

The interior physics of stars is currently not well constrained for early-type stars. This is particularly pertinent for multiple systems as binary interaction becomes more prevalent for more massive stars, which strongly affects their evolution. High-precision photometry from the Transiting Exoplanet Survey Satellite (TESS) mission offers the opportunity to remedy the dearth of observations of pulsating stars that show evidence of binary interaction, specifically pulsating mass-accreting components of semi-detached Algol-type eclipsing binary (oEA) systems. We present the TESS light curve of the circular eclipsing binary system U Gru (TIC 147201138), which shows evidence for free heat-driven pressure modes and a series of tidally-perturbed pressure modes. We highlight the asteroseismic potential of studying pulsating stars in binary systems, and demonstrate how tidal asteroseismology can be applied to infer the influence of binary interaction on stellar structure.