A Class of Eccentric Binaries with Dynamic Tidal Distortions Discovered with Kepler

TL;DR

This paper reports the discovery of a new class of eccentric binary star systems with dynamic tidal distortions and pulsations, characterized by unique light curves and supported by spectroscopic data, expanding the known examples from four to seventeen.

Contribution

It introduces a new class of eccentric binaries with dynamic tides, supported by observational data and preliminary modeling, expanding the understanding of tidal interactions in close binaries.

Findings

Discovered 17 new systems with dynamic tidal features

Supported by spectroscopic radial velocity measurements

Light curve diversity explained by viewing angles

Abstract

We have discovered a class of eccentric binary systems within the Kepler data archive that have dynamic tidal distortions and tidally-induced pulsations. Each has a uniquely shaped light curve that is characterized by periodic brightening or variability at time scales of 4-20 days, frequently accompanied by shorter period oscillations. We can explain the dominant features of the entire class with orbitally-varying tidal forces that occur in close, eccentric binary systems. The large variety of light curve shapes arises from viewing systems at different angles. This hypothesis is supported by spectroscopic radial velocity measurements for five systems, each showing evidence of being in an eccentric binary system. Prior to the discovery of these 17 new systems, only four stars, where KOI-54 is the best example, were known to have evidence of these dynamic tides and tidally-induced oscillations. We perform preliminary fits to the light curves and radial velocity data, present the overall properties of this class and discuss the work required to accurately model these systems.