Investigating Multi-Planet Systems in Alpha Centauri Ab
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Physics and Astronomy
Date of Award
Spring 5-1-2026
Abstract
We investigate the long-term dynamical stability of planetary architectures in the Alpha Centauri AB binary system using high-resolution N-body simulations extending to 10^6 and 10^8 years. A single massive planet (100–300 ��⊕) is placed on a circular orbit around Alpha Centauri A, and the survival of adjacent massless test particles is evaluated as a function of Hill-scaled orbital spacing, ��. To ensure consistent normalization across asymmetric mass configurations, we adopt a generalized mass-weighted Hill radius that interpolates smoothly between the classical single-planet Hill limit and the mutual Hill formulation used in multi-planet studies. Mean particle lifetimes increase systematically with ��, but exhibit localized depressions corresponding to low-order mean-motion resonances, whose locations are predicted analytically. Extended integrations reveal that configurations stable over 106 years can become metastable over secular timescales, demonstrating that the effective stability boundary is time-dependent. Higher planetary masses broaden resonance overlap regions and shrink the long-term stability plateau due to perturbation from the companion star as orbital spacing increases. These results provide a unified framework connecting Hill stability, resonance-driven diffusion, and secular forcing in binary systems, and constrain the viable orbital architectures for planets in the Alpha Centauri system.
Advisor
Billy Quarles
Subject Categories
Astrophysics and Astronomy | Physical Sciences and Mathematics
Recommended Citation
Atuahene, Cavin Afrane, "Investigating Multi-Planet Systems in Alpha Centauri Ab" (2026). Electronic Theses & Dissertations. 1343.
https://lair.etamu.edu/etd/1343
