How do External Companions Affect Spin-Orbit Misalignment of Hot Jupiters?

Abstract

Consider a planet with its orbital angular momentum axis aligned with the spin axis of its host star. To what extent does an inclined distant companion (giant planet or binary star) affect this alignment? We provide an analytic, quantitative answer and apply it to hot Jupiter systems, for which misalignments between the orbital axis and the stellar spin axis have been detected. We also show how similar consideration can be applied to multi-planet systems with distant companions (such as Kepler-56). The result of this paper provides a simple method to assess the dynamical role played by external companions on spin-orbit misalignments in exoplanetary systems.

6 pages, 5 figures, submitted to MNRAS

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Cited by in corpus (13)

• Stellar obliquities in exoplanetary systems
• Evidence for a high mutual inclination between the cold Jupiter and transiting super Earth orbiting $\pi$ Men
• A backward-spinning star with two coplanar planets
• Rotation Periods, Inclinations, and Obliquities of Cool Stars Hosting Directly Imaged Substellar Companions: Spin-Orbit Misalignments are Common
• The misaligned orbit of the Earth-sized planet Kepler-408b
• Kepler-1656b's Extreme Eccentricity: Signature of a Gentle Giant
• Observable Predictions from Perturber-coupled High-eccentricity Tidal Migration of Warm Jupiters
• Confirmation and characterisation of three giant planets detected by TESS from the FIES/NOT and Tull/McDonald spectrographs
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• Excitation of Spin-Orbit Misalignments in Stellar Binaries with Circumbinary Disks: Application to DI Herculis
• Stellar Obliquity Excitation via Disk Dispersal-Driven Resonances in Binaries
• Generating Stellar Obliquity in Systems with Broken Protoplanetary Disks