A resonant-term-based model including a nascent disk, precession, and oblateness: application to GJ 876

摘要: Investigations of two resonant planets orbiting a star or satellites planet often rely on few and secular terms in order to obtain representative quantitative description the system’s dynamical evolution. We present semianalytic model which traces orbital evolution any bodies first- through fourth-order eccentricity inclination-based resonance dominated by arguments user’s choosing. By considering variation libration width with different parameters, we identify regions phase space give rise “depths,” propose methods profiles. apply GJ 876 extrasolar planetary system, quantify relative importance relevant contributions, thereby assess goodness common approximation representing system just presumably dominant terms. highlight danger using “order” as metric for accuracy solution revealing unnatural centers produced second-order, but not first-order, solution, demonstrating that true lies somewhere “in-between” third- solutions. also formulas used incorporate perturbations from central-body oblateness precession, protoplanetary protosatellite thin disk gaps, into system. contributions these conditions must exist multi-planet exosystems be significantly influenced such factors. find massive enough disks may convert circulation; disk-induced signatures provide constraints future studies exoplanet systems.