Compact planetary systems perturbed by an inclined companion: II. Stellar spin-orbit evolution

Abstract

The stellar spin orientation relative to the orbital planes of multiplanet systems are becoming accessible to observations. Here, we analyze and classify different types of spin-orbit evolution in compact multiplanet systems perturbed by an inclined outer companion. Our study is based on classical secular theory, using a vectorial approach developed in a separate paper. When planet-planet perturbations are truncated at the second order in eccentricity and mutual inclination, and the planet-companion perturbations are developed at the quadrupole order, the problem becomes integrable. The motion is composed of a uniform precession of the whole system around the total angular momentum, and in the rotating frame, the evolution is periodic. Here, we focus on the relative motion associated to the oscillations of the inclination between the planet system and the outer orbit, and of the obliquities of the star with respect to the two orbital planes. The solution is obtained using a powerful geometric method. With this technique, we identify four different regimes characterized by the nutation amplitude of the stellar spin-axis relative to the orbital plane of the planets. In particular, the obliquity of the star reaches its maximum when the system is in the Cassini regime where planets have more angular momentum than the star, and where the precession rate of the star is similar to that of the planets induced by the companion. In that case, spin-orbit oscillations exceed twice the inclination between the planets and the companion. Even if mutual inclination is only ~ 20 deg, this resonant case can cause the spin-orbit angle to oscillate between perfectly aligned and retrograde values.

29 pages, 15 figures, accepted for publication in ApJ

References in corpus (9)

• The Occurrence and Mass Distribution of Close-in Super-Earths, Neptunes, and Jupiters
• Formation of Hot Planets by a combination of planet scattering, tidal circularization, and Kozai mechanism
• Radial velocity planets de-aliased. A new, short period for Super-Earth 55 Cnc e
• Five Planets Orbiting 55 Cancri
• Alignment of the stellar spin with the orbits of a three-planet system
• Satellite dynamics on the Laplace surface
• Tidal evolution of hierarchical and inclined systems
• Planetary Systems in Binaries. I. Dynamical Classification
• Compact planetary systems perturbed by an inclined companion: I. Vectorial representation of the secular model

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