Hidden population of Algols

TL;DR

This study uses Monte Carlo simulations to estimate the hidden population of Algol-type binaries among stars, revealing that a significant fraction remains undetected due to observational biases, impacting stellar statistics.

Contribution

The paper introduces a simulation-based approach to estimate the true frequency of Algol binaries accounting for detection biases and unobserved systems.

Findings

Estimated 0.1-0.2% of stars are Algols after bias correction

Hidden binarity significantly affects stellar population statistics

Detection biases cause many Algols to remain unresolved in surveys

Abstract

We present results of Monte Carlo simulation aiming at the estimate of the frequency of semi-detached Algol-type binaries among the stars observed as single ones. When account is made for various detection biases (mostly due to inclination of orbits), the fraction of Algols among Galactic disk stars appears to be 0.1--0.2\%. However, this number should be regarded as a lower limit only, since there are still unaccounted selection effects and other types of photometrically unresolved binaries. Hidden binarity appears to be an important phenomenon that should be taken into account when considering stellar statistics and construction of fundamental relations between stellar parameters.