Formation of Earth-sized planets within the Kepler-1647 System Habitable Zone

TL;DR

This study explores the potential for forming Earth-sized planets and moons within the habitable zone of the Kepler-1647 binary system, using numerical simulations to identify stable regions and formation conditions.

Contribution

It provides the first detailed analysis of planetary and moon formation potential within Kepler-1647's habitable zone through stability tests and formation simulations.

Findings

Identified three stable sub-regions in the habitable zone.

Many resonances cause disc material ejection, affecting planet formation.

Potential for Trojan bodies and stable Earth-sized moons up to 0.4 Hill's radius.

Abstract

The Kepler-1647 is a binary system with two Sun-type stars (approximately 1.22 and 0.97 Solar mass). It has the most massive circumbinary planet (1.52 Jupiter mass) with the longest orbital period (1,107.6 days) detected by the Kepler probe and is located within the habitable zone (HZ) of the system. In this work, we investigated the ability to form and house an Earth-sized planet within its HZ. First, we computed the limits of its HZ and performed numerical stability tests within that region. We found that HZ has three sub-regions that show stability, one internal, one co-orbital, and external to the host planet Kepler-1647b. Within the limits of these three regions, we performed numerical simulations of planetary formation. In the regions inner and outer to the planet, we used two different density profiles to explore different conditions of formation. In the co-orbital region, we used eight different values of total disc mass. We showed that many resonances are located within regions causing much of the disc material to be ejected before a planet is formed. Thus, the system might have two asteroid belts with Kirkwood gaps, similar to the Solar System\'s main belt of asteroids. The co-orbital region proved to be extremely sensitive, not allowing the planet formation, but showing that this binary system has the capacity to have Trojan bodies. Finally, we looked for regions of stability for an Earth-sized moon. We found that there is stability for a moon with this mass up to 0.4 Hill\'s radius from the host planet.