Binary stars: a cheat sheet

TL;DR

This paper summarizes the types of binary stars, emphasizing eclipsing binaries as key sources for precise stellar mass and radius measurements, which are crucial for testing and refining stellar models.

Contribution

It provides a concise overview of binary star types, their observable properties, and highlights the importance of eclipsing binaries for accurate stellar parameter determination.

Findings

Eclipsing binaries allow mass and radius measurements with better than 1% accuracy.

These measurements serve as vital empirical data for stellar model validation.

Preliminary results are presented for a specific solar-type eclipsing binary.

Abstract

I present a brief summary of three different types of binary star - astrometric, spectroscopic and eclipsing - and tabulate the properties of these systems that can be determined directly from observations. Eclipsing binary stars are the most valuable of these, as they are our main source of direct mass and radius measurements for normal stars. In good cases, masses and radii can be obtained to better than 1% precision and accuracy using only photometry, spectroscopy and geometry. These measurements constitute vital empirical data against which theoretical models of stars can be verified and improved. I give examples of the use of these systems for constraining stellar theory and the distance scale, and conclude with a presentation of preliminary results for the solar-type eclipsing binary 1SWASP J034114.25+201253.5.