# HIDES spectroscopy of bright detached eclipsing binaries from the $Kepler$ field - II. Double- and triple-lined objects

## TL;DR

This study uses high-resolution spectroscopy and Kepler light curves to precisely determine the physical parameters of eight detached eclipsing binaries, revealing new triple systems and analyzing their orbital dynamics and evolutionary states.

## Contribution

It provides detailed orbital and physical parameters for eight DEBs, including two triples, using combined spectroscopic and photometric data, and assesses their evolutionary status.

## Key findings

- Achieved below 3% precision in masses and radii for five binary systems.
- Identified a new gamma Dor pulsator in an eclipsing binary.
- Discovered two triple systems with measurable orbital motions.

## Abstract

We present the results of our spectroscopic observations of eight detached eclipsing binaries (DEBs), selected from the $Kepler$ Eclipsing Binary Catalog. Radial velocities (RVs) were calculated from high resolution spectra obtained with the HIDES pectrograph, attached to the 1.88-m telescope of the Okayama Astrophysical Observatory, and were used to characterize the targets in combination with the $Kepler$ light curves. For each binary we obtained a full set of orbital and physical parameters, reaching precision below 3% in masses and radii for 5 pairs. By comparing our results with theoretical models, we assess the distance, age and evolutionary status of the researched objects. We also study eclipse timing variations of selected objects, and identify a new system with a $\gamma$Dor pulsator. Two systems are triples, and show lines coming from three components. In one case the motion of the outer star and the perturbation in the RVs of the inner binary are clearly visible and periodical, which allows us to directly calculate the mass of the third star, and inclination of the outer orbit. In the second case we only see a clear motion of the tertiary, and investigate two scenarios: that it is a linear trend coming from the orbital motion around the inner binary, and that it is caused by a planetary mass companion. When possible, we also compare our results with the literature, and conclude that only by combining photometry with RVs it is possible to obtain correct physical parameters of both components of a DEB.