Spin Dynamics of Planets in Resonant Chains

• DOI: 10.3847/1538-4357/ad10a0
• Publication Date: 2024-01-26T11:39:44Z
• Authors: Sarah C. Millholland; Teo Lara; Jan Toomlaid
• Keywords: Dynamics

Abstract About a dozen exoplanetary systems have been discovered with three or more planets participating in sequence of mean-motion resonances. The unique and complex architectures these so-called “resonant chains” motivate efforts to characterize their holistically. In this work, we perform comprehensive exploration the spin-axis dynamics resonant chains. Planetary spin states are closely linked atmospheric habitability thus especially relevant chains like TRAPPIST-1, which hosts several temperate planets. Considering set observed chains, calculate equilibrium planetary axial tilts (“obliquities”). We show that high-obliquity exist for ∼60% our sample, many can be stable presence tidal dissipation. Using case studies two (Kepler-223 TOI-1136), demonstrate how could attained during initial epoch disk-driven orbital migration established architectures. TRAPPIST-1 most likely zero obliquities, possible exception planet d. Overall, results highlight both valuable relics early stages formation evolution.