Astronomy7 papers
Mean-motion resonances in 2025
by Evgeny Smirnov
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Resonance Capture of a Test Particle by an Eccentric Planet in the Presence of Externally-Driven Apsidal Precession
Laune, JT & Lai, Dong (2025)
- Published
- May 1, 2025
- Journal
- arXiv e-prints
- DOI
- 10.48550/arXiv.2505.09937
At a GlanceAI
Small externally driven differential apsidal precession can strongly disrupt capture into first-order mean-motion resonances.
SummaryAI
The paper examines how externally imposed differential apsidal precession modifies capture into first-order mean-motion resonances for a test particle interacting with an eccentric, migrating planet. It shows that even very small differential precession rates can disrupt capture by splitting resonances into sub-resonances and producing two critical precession frequencies (resonance-overlap and secular apsidal resonance) that reduce capture likelihood, with implications for Neptune-era trans-Neptunian object capture.
Method Snapshot
semi-analytical Hamiltonian model in eccentric R3B + numerical integration + FLI
Background
Hamiltonian mechanism, mean-motion resonances, FLI, and secular (apsidal) precession is needed to follow the results.
AI Abstract
Planets undergoing convergent migration can be captured into mean-motion resonance (MMR), where their orbital periods are related by integer ratios. MMR dynamics are usually modeled including only the forces between the planets and the central star, but external forces can induce apsidal precession that splits an MMR into two sub-resonances and can cause chaotic motion via resonance overlap. This study investigates how externally induced differential apsidal precession affects capture into first-order j:j+1 MMRs by analyzing the restricted three-body problem for a test particle exterior to an eccentric planet that undergoes outward migration. We find that capture can be sensitive to the differential apsidal precession even when the precession rate is much smaller than the usual resonance-overlap criterion, and we identify two critical precession frequencies—one related to resonance overlap and one to secular apsidal resonance—around which capture is disrupted even for very small planet eccentricity. These results have implications for the capture of resonant trans-Neptunian objects during Neptune's outward migration in the early Solar System.
External planets cause orbits to rotate at different rates, and this manuscript shows that even small mismatches can prevent capture in MMR... (though, I'm unsure whether I've got this right...)
— ES