摘要：AbstractWe present the results of Monte Carlo simulation aiming to estimate the frequency of semi-detached Algol-type binaries among the stars observed as single. When an account is taken of various detection biases (mostly due to inclination of orbits), the fraction of Algols among the 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-for 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 constructing the fundamental relations between stellar parameters.
