Calculating the Habitable Zone of Binary Star Systems I: S-Type Binaries

TL;DR

This paper introduces a comprehensive method for calculating the habitable zone boundaries in S-type binary star systems, considering stellar contributions, binary eccentricity, and spectral types, with applications to known binaries.

Contribution

The paper presents a novel, general methodology for determining habitable zones in binary systems that accounts for stellar types and orbital parameters, improving previous models.

Findings

Secondary star's luminosity can significantly affect the habitable zone.

Binary eccentricity influences the extent of the habitable zone.

Method applied successfully to known planet-hosting binaries.

Abstract

We have developed a comprehensive methodology for calculating the boundaries of the habitable zone (HZ) of planet-hosting S-type binary star systems. Our approach is general and takes into account the contribution of both stars to the location and extent of the Binary HZ with different stellar spectral types. We have studied how the binary eccentricity and stellar energy distribution affect the extent of the habitable zone. Results indicate that in binaries where the combination of mass-ratio and orbital eccentricity allows planet formation around a star of the system to proceed successfully, the effect of a less luminous secondary on the location of the primary's habitable zone is generally negligible. However, when the secondary is more luminous, it can influence the extent of the HZ. We present the details of the derivations of our methodology and discuss its application to the Binary HZ around the primary and secondary main sequence stars of an FF, MM, and FM binary, as well as two known planet-hosting binaries alpha Cen AB and HD 196886.