2023/05/29 by Yue Chen, Jian Li, Chen, Yue +1
Physics and Astronomy · #Astro and Planetary Science #Earth and Planetary Astrophysics (astro-ph.EP) #FOS: Physical sciences #Solar and Space Plasma Dynamics #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2305.18157
openalex publication_date 2023/05/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
As the second part of our study, in this paper, we proceed to refine the solar system model by incorporating the gravitational influence of Plutinos in Neptune's 2:3 resonance. We aim to develop the arc model to represent the global perturbation of Plutinos by taking into account their asymmetric spatial distribution resulting from the 2:3 resonance, and demonstrate the difference to the commonly employed ring model. The global perturbation of Plutinos is measured by the change in the Sun-Neptune distance. We begin by deriving the number density of the discrete-arc comprised of point masses to accurately represent the continuous-arc. Based on the resonant characteristics of the 2:3 MMR, we then construct three overlapping discrete-arcs to model the Plutinos. The perturbations of these arcs are investigated in detail, considering various azimuthal and radial distributions associated with the resonant amplitudes A and eccentricities e of the Plutinos, respectively. The change in Sun-Neptune distance, i.e. ΔdSN, caused by Plutinos increases as the range of A widens. At e<=0.1, ΔdSN can reach magnitudes on the order of 100 km. However, the effects of Plutinos' A and e can possibly balance each other. As given e>=0.25, we find that ΔdSN approaches zero, indicating a negligible contribution from highly eccentric Plutinos to the planetary ephemerides. We finally provide a concise analytic expression, which contains the parameters A, e and the total mass of Plutinos, to estimate ΔdSN at any epoch from 2020 to 2120. Furthermore, since the difference in ΔdSN between the arc and ring model can be as large as 170 km, we conclude that the ring model is unsuitable for representing the perturbations of Plutinos. The idea of the multiple-arc model designed for Plutinos can be readily generalized to other MMRs heavily populated by small bodies.