Orbital and physical parameters of eclipsing binaries from the ASAS catalogue -- XI. CHIRON investigation of long-period binaries

TL;DR

This study investigates long-period eclipsing binaries using spectroscopic and photometric data, deriving physical and orbital parameters, with a focus on evolved stars and stellar evolution insights.

Contribution

It presents new orbital and physical solutions for seven long-period eclipsing binaries, including precise mass and radius measurements for four systems.

Findings

Most targets are evolved stars like sub-giants or red giants.

Four binaries have component masses and radii measured with better than 3% precision.

The study provides valuable data on stellar evolution processes.

Abstract

We present the results of a spectroscopic campaign on eclipsing binaries with long orbital period (P = 20 - 75 d) carried out with the CHIRON spectrograph. Physical and orbital solutions for seven systems were derived from the V-band, and I-band ASAS, WASP, and TESS photometry, while radial velocities were calculated from high quality optical spectra using a two-dimensional cross-correlation technique. The atmospheric parameters of the stars have been determined from the separated spectra. Most of our targets are composed of evolved stars (sub-giants or red giants) but two systems show components in different phases of evolution and one possible merger. For four binaries the masses and radii of the components were obtained with precision better than 3%. These objects provide very valuable information on stellar evolution.