Primordial giant planet obliquity driven by a circumplanetary disk

Abstract

Detached circumplanetary disks are unstable to tilting as a result of the stellar tidal potential. We examine how a tilted circumplanetary disk affects the evolution of the spin axis of an oblate planet. The disk is evolved using time-dependent equations for linear wave-like warp evolution, including terms representing the effect of the tidal potential and planetary oblateness. For a disk with a sufficiently large mass, we find that the planet spin quickly aligns to the misaligned disk. The tilt of the planetary spin axis then increases on the same timescale as the disk. This can be an efficient mechanism for generating primordial obliquity in giant planets. We suggest that directly imaged exoplanets at large orbital radii, where the disk mass criterion is more likely to be satisfied, could have significant obliquities due to the tilt instability of their circumplanetary disks.

Accepted for publication in ApJL

References in corpus (12)

• Accreting Circumplanetary Disks: Observational Signatures
• Giant Outbursts in Be/X-ray Binaries
• Formation of Giant Planet Satellites
• Tidal Torques on Misaligned Disks in Binary Systems
• Alignment and Precession of a Black Hole with a Warped Accretion Disc
• Linear Analysis of the Evolution of Nearly Polar Low Mass Circumbinary Discs
• Shock-driven Accretion in Circumplanetary Disks: Observables and Satellite Formation
• Generalised warped disk equations
• Excitation of Planetary Obliquities Through Planet-Disk Interactions
• The future large obliquity of Jupiter
• A fast-growing tilt instability of detached circumplanetary disks
• Kozai-Lidov oscillations triggered by a tilt instability of detached circumplanetary discs

Cited by in corpus (5)

• Primordial Obliquities of Brown Dwarfs and Super-Jupiters from Fragmenting Gravito-Turbulent Discs
• Leaning Sideways: VHS 1256-1257 b is a Super-Jupiter with a Uranus-like Obliquity
• Future destabilisation of Titan as a result of Saturn's tilting
• Obliquity Constraints on the Planetary-mass Companion HD 106906 b
• Planetary Obliquity Excitation Through Pre-Main Sequence Stellar Evolution