Astronomical Cardiology: A Search For Heartbeat Stars Using $\textit{Gaia}$ and $\textit{TESS}$

TL;DR

This paper identifies 112 new heartbeat star systems using Gaia and TESS data, analyzes their orbital parameters, and explores their stellar evolution and population characteristics.

Contribution

It introduces a method combining Gaia spectroscopic data and TESS photometry to discover and characterize heartbeat stars, including mass and radius measurements for select systems.

Findings

85% of single-line binaries have consistent orbital parameters

20% of double-line binaries show consistent orbits

Heartbeat star fraction increases with stellar temperature

Abstract

Heartbeat stars are a subclass of binary stars with short periods, high eccentricities, and phase-folded light curves that resemble an electrocardiogram. We start from the $\textit{Gaia}$ catalogs of spectroscopic binaries and use $\textit{TESS}$ photometry to identify 112 new heartbeat star systems. We fit their phase-folded light curves with an analytic model to measure their orbital periods, eccentricities, inclinations, and arguments of periastron. We then compare these orbital parameters to the $\textit{Gaia}$ spectroscopic orbital solution. Our periods and eccentricities are consistent with the $\textit{Gaia}$ solutions for 85$\%$ of the single-line spectroscopic binaries but only 20$\%$ of the double-line spectroscopic binaries. For the two double-line spectroscopic binary heartbeat stars with consistent orbits, we combine the $\textit{TESS}$ phase-folded light curve and the $\textit{Gaia}$ velocity semi-amplitudes to measure the stellar masses and radii with $\texttt{PHOEBE}$. In a statistical analysis of the heartbeat star population, we find that non-giant heartbeat stars have evolved off the main sequence and that the fraction of the systems that are heartbeat stars rises rapidly with effective temperature.