Earth-size planet formation in the habitable zone of circumbinary stars

Abstract

In this work is investigated the possibility of close-binary star systems having Earthsize planets within their habitable zones. First, we selected all known close-binary systems with confirmed planets (totaling 22 systems) to calculate the boundaries of their respective habitable zones (HZ). However, only eight systems had all the data necessary for the computation of the HZ. Then, we numerically explored the stability within the habitable zones for each one of the eight systems using test particles. From the results, we selected five systems that have stable regions inside the habitable zones (HZ), namely 35, 38, 413 and 453. For these five cases of systems with stable regions in the HZ, we perform a series of numerical simulations for planet formation considering disks composed of planetary embryos and planetesimals, with two distinct density profiles, in addition to the stars and host planets of each system. We found that in the case of Kepler-34 and 453 systems no Earth-size planet is formed within the habitable zones. Although planets with Earth-like masses were formed in the Kepler-453, but they were outside the HZ. In contrast, for Kepler-35 and 38 systems, the results showed that potentially habitable planets are formed in all simulations. In the case of the Kepler-413 system, in just one simulation a terrestrial planet was formed within the habitable zone.

Running The Gauntlet -- Survival of Small Circumbinary Planets Migrating Through Destabilising Resonances

“…If small circumbinary planets truly do not exist, then there are two broad explanations: 1; they cannot form, or 2; they do form but cannot survive. With respect to formation, the simulations of Barbosa et al (2020); Childs & Martin (2021b,a) do produce terrestrial circumbinary planets, although the presence of a giant planet may be an inhibitor. With respect to migration, Sutherland & Kratter (2019) demonstrated that multi-planet circumbinary systems may have a complex interplay between planet-planet and binary-planet resonances, potentially leading to ejections.…”

Dynamics and habitability of the TESS circumbinary systems TOI-1338 and TIC-172900988

“…From planetary formation theories it is possible to have such type of systems (e.g. Barbosa et al 2020Barbosa et al , 2021. We found that for the various orbital solutions of TOI-1338 and TIC-172900988 investigated, the Earth mass planetary orbit showed minimal variations in the semimajor axis and some small changes in the eccentricity.…”

Terrestrial planet formation in a circumbinary disc around a coplanar binary

“…The late stages of in situ terrestrial planet formation for CBPs in coplanar discs have previously been numerically studied (e.g. Quintana & Lissauer 2006;Quintana & Lissauer 2007;Quintana 2008;Quintana & Lissauer 2010;Gong et al 2013;Lines et al 2014;Barbosa et al 2020). While widely separated, eccentric binaries can inhibit CBP formation, planetary systems can form for a range of binary mass fractions and orbits.…”