# KIC 8164262: a Heartbeat Star Showing Tidally Induced Pulsations with Resonant Locking

## TL;DR

This paper analyzes KIC 8164262, a heartbeat star with tidally induced pulsations, revealing a resonant locking mechanism that explains its prominent oscillation mode through combined photometric and spectroscopic data.

## Contribution

It provides a detailed binary star model of KIC 8164262, demonstrating the presence of a tidally resonant pulsation and introducing the concept of resonance locking in heartbeat stars.

## Key findings

- Detection of a high-amplitude pulsation at 229 times the orbital frequency.
- Identification of a highly eccentric orbit (e=0.886) with a slightly evolved F star and M secondary.
- Evidence supporting a resonance locking mechanism for the pulsation mode.

## Abstract

We present the analysis of KIC 8164262, a heartbeat star with a high-amplitude (~1 mmag), tidally resonant pulsation (a mode in resonance with the orbit) at 229 times the orbital frequency and a plethora of tidally induced g-mode pulsations (modes excited by the orbit). The analysis combines Kepler light curves with follow-up spectroscopic data from the Keck telescope, KPNO (Kitt Peak National Observatory) 4-m Mayal telescope and the 2.7-m telescope at the McDonald observatory. We apply the binary modelling software, PHOEBE, to the Kepler light curve and radial velocity data to determine a detailed binary star model that includes the prominent pulsation and Doppler boosting, alongside the usual attributes of a binary star model (including tidal distortion and reflection). The results show that the system contains a slightly evolved F star with an M secondary companion in a highly eccentric orbit (e = 0.886). We use the results of the binary star model in a companion paper (Fuller et al., 2017) where we show that the prominent pulsation can be explained by a tidally excited oscillation mode held near resonance by a resonance locking mechanism.