Orbital and physical parameters of eclipsing binaries from the ASAS catalogue -- XII. A sample of systems with $K2$ photometry

TL;DR

This study analyzes light and radial velocity data of eight eclipsing binary systems observed by ASAS and K2, deriving stellar parameters and ages, with five systems analyzed for the first time, revealing diverse stellar types and evolutionary states.

Contribution

The paper provides new detailed stellar parameters for eight eclipsing binaries, including five systems analyzed for the first time, using combined photometric and spectroscopic data from multiple instruments.

Findings

Derived masses, radii, and ages for eight binary systems.

Identified a variety of stellar types, including low-mass dwarfs and evolved sub-giants.

Detected potential gamma Dor pulsator and higher-order multiple systems.

Abstract

We present results of the analysis of light and radial velocity (RV) curves of eight detached eclipsing binaries observed by the All-Sky Automated Survey, which we have followed up with high-resolution spectroscopy, and were later observed by the $Kepler$ satellite as part of the $K2$ mission. The RV measurements came from spectra obtained with OAO-188/HIDES, MPG-2.2m/FEROS, SMARTS 1.5m/CHIRON, Euler/CORALIE, ESO-3.6m/HARPS, and OHP-1.93/ELODIE instruments. The $K2$ time-series photometry was analyzed with the JKTEBOP code, with out-of-eclipse modulations of different origin taken into account. Individual component spectra were retrieved with the FD3 code, and analyzed with the code iSpec in order to determine effective temperatures and metallicities. Absolute values of masses, radii, and other stellar parameters are calculated, as well as ages, found through isochrone fitting. For five systems such analysis has been done for the first time. The presented sample consists of a variety of stars, from low-mass dwarfs, through G and F-type Main Sequence objects, to evolved active sub-giants, one of which is found to be crossing the Hertzsprung gap. One target may contain a $\gamma$ Dor-type pulsator, two more are parts of higher-order multiples, and spectra of their tertiaries were also retrieved and used to constrain the properties of these systems.