Exomoons In The Habitable Zones Of M Dwarfs

M dwarfs host most of the exoplanets in the local Milky Way. Some of these planets, ranging from sub-Earths to super-Jupiters, orbit in their stars’ habitable zones, although many likely possess surface environments that preclude habitability.

Moreover, exomoons around these planets could harbor life for long timescales and thus may also be targets for biosignature surveys. Here we investigate the potential habitability, stability, and detectability of exomoons around exoplanets orbiting M dwarfs.

We first compile an updated list of known M-dwarf exoplanet hosts, comprising 109 stars and 205 planets. For each M dwarf, we compute and update precise luminosities with the Virtual Observatory SED Analyzer and Gaia DR2 parallaxes to determine inner and outer boundaries of their habitable zones. For each planet, we retrieve (or, when necessary, homogeneously estimate) their masses and radii, calculate the long-term dynamical stability of hypothetical moons, and identify those planets that can support habitable moons.

We find that 33 exoplanet candidates are located in the habitable zones of their host stars and that four of them could host Moon- to Titan-mass exomoons for timescales longer than the Hubble time.

Héctor Martínez-Rodríguez, José Antonio Caballero, Carlos Cifuentes, Anthony L. Piro, Rory Barnes
(Submitted on 26 Oct 2019)
Comments: 30 pages, 5 figures, 6 tables
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:1910.12054 [astro-ph.EP] (or arXiv:1910.12054v1 [astro-ph.EP] for this version)
Submission history
From: Héctor Martínez-Rodríguez
[v1] Sat, 26 Oct 2019 12:28:10 UTC (798 KB)
https://arxiv.org/abs/1910.12054
Astrobiology, Astrochemistry