Circumbinary Components of Contact Binaries

TL;DR

This paper investigates the chaotic and cyclic period changes in contact binary stars, suggesting that third components may cause observed cyclic variations, with examples illustrating these phenomena.

Contribution

It identifies cyclic period changes in contact binaries and attributes them to third components, providing observational examples and analysis.

Findings

Chaotic period changes are common in contact binaries.

Cyclic changes are likely caused by third components.

Examples demonstrate the presence of third components in contact binaries.

Abstract

The period changes of contact binaries obtained by the analysis of eclipse minima timing are found mostly chaotic in nature. However, they are representable by a few cyclic changes superposed on a secular change. The cyclic changes are caused most probably by the third components revolving around the contact binaries. Some typical examples of the period changes of contact binaries are presented in the present contribution.