Orbital and Pulsation Analysis of 42 Heartbeat Stars Discovered in TESS Data

TL;DR

This study identifies 42 new heartbeat stars from TESS data, analyzes their pulsations and tidal interactions, and explores their physical properties and evolutionary states, providing new insights into binary star dynamics.

Contribution

The paper presents the discovery of 42 new heartbeat stars and detailed analysis of their pulsations and tidal interactions, expanding the known sample and understanding of eccentric binary systems.

Findings

10 systems show tidally excited oscillations (TEOs)

Most pulsation phases align with spherical harmonic degree l=2

Eccentricity correlates positively with orbital period

Abstract

Heartbeat stars (HBSs) are ideal laboratories for studying the formation and evolution of binary stars in eccentric orbits and their mutual tidal interactions. We present 42 new HBSs discovered based on TESS-SPOC and QLP data. Their physical parameters have been obtained through modeling with appropriate models. Subsequently, Tidally excited oscillations (TEOs) are detected in ten systems, and their pulsation phases and modes are identified. Most pulsation phases can be explained by the dominant being spherical harmonic degree $l=2$ and azimuthal order $m=0$ or $\pm2$. For TIC 156846634, the harmonic with large deviation ($>3\sigma$) from the expected adiabatic phase can be expected to be a traveling wave or significantly nonadiabatic. The harmonic numbers $n$ = 16 in TIC 184413651 may not be considered as a TEO candidate due to its large deviation ($>2\sigma$) from the adiabatic expectation. Moreover, TIC 92828790 shows no TEOs but exhibits a significant $\gamma$\,Dor-type pulsation. The eccentricity-period ($e-P$) relation also shows a positive correlation between eccentricity and period, as well as the existence of orbital circularization. The Hertzsprung-Russell diagram shows that TESS HBSs have higher temperatures and greater luminosities than Kepler HBSs, possibly due to selection effects. This significantly enhances the detectability of massive HBSs and those containing TEOs.