Impact of Tides on the Potential for Exoplanets to Host Exomoons

Abstract

Exomoons may play an important role in determining the habitability of worlds outside of our solar system. They can stabilize conditions, alter the climate by breaking tidal locking with the parent star, drive tidal heating, and perhaps even host life themselves. However, the ability of an exoplanet to sustain an exomoon depends on complex tidal interactions. Motivated by this, we make use of simplified tidal lag models to follow the evolution of the separations and orbital and rotational periods in planet, star, and moon systems. We apply these models to known exoplanet systems to assess the potential for these exoplanets to host exomoons. We find that there are at least 36 systems in which an exoplanet in the habitable zone may host an exomoon for longer than one gigayear. This includes Kepler-1625b, an exoplanet with an exomoon candidate, which we determine would be able to retain a Neptune-sized moon for longer than a Hubble time. These results may help provide potential targets for future observation. In many cases, there remains considerable uncertainty in the composition of specific exoplanets. We show the detection (or not) of an exomoon would provide an important constraint on the planet structure due to differences in their tidal response.

13 pages, 13 figures, updated with minor changes to match version accepted for publication in AJ

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Cited by in corpus (12)

• Eta-Earth Revisited II: Deriving a Maximum Number of Earth-like Habitats in the Galactic Disk
• The ominous fate of exomoons around hot Jupiters in the high-eccentricity migration scenario
• A target list for searching for habitable exomoons
• Stability and detectability of exomoons orbiting HIP 41378 f, a temperate Jovian planet with an anomalously low apparent density
• Pathways of Survival of Exomoons and Inner Exoplanets
• Consequences of dynamically unstable moons in extrasolar systems
• Tidal Heating of Exomoons in Resonance and Implications for Detection
• On the Stability of Additional Moons Orbiting Kepler-1625 b
• Probing Planets with Exomoons: The Cases of Kepler-1708 b and Kepler-1625 b
• Multiverse Predictions for Habitability: Planetary Characteristics
• The Dynamics of Co-orbital Giant Exomoons -- Applications for the Kepler-1625 b and Kepler-1708 b Satellite Systems
• Survival of exomoons around exoplanets