Review of candidates of binary systems with an RR Lyrae component

TL;DR

This paper reviews the current research status on binary systems containing RR Lyrae stars, highlighting the increased number of candidates and discussing detection methods, orbital parameters, and the Blazhko effect.

Contribution

It provides a comprehensive overview of recent findings and challenges in identifying RR Lyrae stars in binary systems, emphasizing the higher-than-expected occurrence.

Findings

Number of binary candidates has increased significantly.

Detection probability varies with observing methods.

Orbital parameters and the Blazhko effect are actively studied.

Abstract

We present an overview and current status of research on RR Lyrae stars in binary systems. In present days the number of binary candidates has steeply increased and suggested that multiple stellar systems with an RR Lyrae component is much higher than previously thought. We discuss the probability of their detection using various observing methods, compare recent results regarding selection effects, period distribution, proposed orbital parameters and the Blazhko effect.