Solar Obliquity Induced by Planet Nine

Abstract

The six-degree obliquity of the sun suggests that either an asymmetry was present in the solar system's formation environment, or an external torque has misaligned the angular momentum vectors of the sun and the planets. However, the exact origin of this obliquity remains an open question. Batygin & Brown (2016) have recently shown that the physical alignment of distant Kuiper Belt orbits can be explained by a 5-20 Earth-mass planet on a distant, eccentric, and inclined orbit, with an approximate perihelion distance of ~250 AU. Using an analytic model for secular interactions between Planet Nine and the remaining giant planets, here we show that a planet with similar parameters can naturally generate the observed obliquity as well as the specific pole position of the sun's spin axis, from a nearly aligned initial state. Thus, Planet Nine offers a testable explanation for the otherwise mysterious spin-orbit misalignment of the solar system.

8 pages, 4 figures, manuscript #: AAS01477, submitted on June 24, 2016

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Cited by in corpus (22)

• The Planet Nine Hypothesis
• Origin and Evolution of Short-Period Comets
• Origin and evolution of long-period comets
• Generation of Highly Inclined Trans-Neptunian Objects by Planet Nine
• Rotation Periods, Inclinations, and Obliquities of Cool Stars Hosting Directly Imaged Substellar Companions: Spin-Orbit Misalignments are Common
• Solar System Physics for Exoplanet Research
• Dynamical Evolution Induced by Planet Nine
• Numerical Solutions for the orbital motion of the Solar System over the Past 100 Myr: Limits and new results
• The inclination of the planetary system relative to the solar equator may be explained by the presence of Planet 9
• Constraints on Planet Nine's Orbit and Sky Position within a Framework of Mean Motion Resonances
• Consequences of a Distant Massive Planet on the Large Semi-major Axis Trans-Neptunian Objects
• Non-resonant secular dynamics of trans-Neptunian objects perturbed by a distant super-Earth
• OSSOS XV: Probing the Distant Solar System with Observed Scattering TNOs
• Evaluating the Dynamical Stability of Outer Solar System Objects in the Presence of Planet Nine
• Orbital precession in the distant solar system; further constraining the Planet Nine hypothesis with numerical simulations
• Stability of Neptune's distant resonances in the presence of Planet Nine
• Outer Solar System Perihelion Gap Formation Through Interactions with a Hypothetical Distant Giant Planet
• Stellar winds as a mechanism to tilt the spin axes of Sun-like stars
• What Would Happen If We Were About 1 pc Away from a Supermassive Black Hole?
• Assessing the spin-orbit obliquity of low-mass planets in the breaking the chain formation model: A story of misalignment
• Calibration of the angular momenta of the minor planets in the solar system
• Mean plane of the Kuiper belt beyond 50 AU in the presence of Planet 9