Calculating the Habitable Zone of Binary Star Systems II: P-Type Binaries

TL;DR

This paper introduces a detailed method for calculating the habitable zone in P-type binary star systems, accounting for stellar contributions, orbital dynamics, and applying it to known systems.

Contribution

It provides a general formalism for determining the circumbinary habitable zone boundaries considering stellar flux and orbital motion effects.

Findings

The habitable zone boundaries vary with stellar luminosity, spectral types, and binary eccentricity.

Application to Kepler systems demonstrates the method's practical utility.

The habitable zone is dynamic, changing with binary orbital motion.

Abstract

We have developed a comprehensive methodology for calculating the circumbinary HZ in planet-hosting P-type binary star systems. We present a general formalism for determining the contribution of each star of the binary to the total flux received at the top of the atmosphere of an Earth-like planet, and use the Sun's HZ to calculate the locations of the inner and outer boundaries of the HZ around a binary star system. We apply our calculations to the Kepler's currently known circumbinary planetary system and show the combined stellar flux that determines the boundaries of their HZs. We also show that the HZ in P-type systems is dynamic and depending on the luminosity of the binary stars, their spectral types, and the binary eccentricity, its boundaries vary as the stars of the binary undergo their orbital motion. We present the details of our calculations and discuss the implications of the results.