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Shepherding in a Self-gravitating Disk of Trans-Neptunian Objects
Antranik A Sefilian1, Jihad R Touma2
1Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Centre for Mathematical Sciences, Wilberforce Road, Cambridge CB3 0WA, UK; aas79@damtp.cam.ac.uk.
The Astronomical Journal
|February 8, 2021
Summary
A massive disk of trans-Neptunian objects (TNOs) can explain the unusual orbits of some TNOs by counteracting planetary forces. This "shepherding disk" hypothesis offers an alternative to a hypothetical Planet Nine.
Area of Science:
- Astronomy
- Planetary Science
- Astrophysics
Background:
- The orbits of trans-Neptunian objects (TNOs) exhibit clustering that challenges current solar system models.
- The existence of a massive, eccentric disk of TNOs has been proposed to explain these orbital anomalies.
Purpose of the Study:
- To investigate the dynamical effects of a massive trans-Neptunian debris disk on TNO orbital evolution.
- To determine if such a disk can replicate observed TNO orbital properties, potentially explaining the need for a Planet Nine.
Main Methods:
- Simulations of orbital dynamics involving giant planets and a self-gravitating TNO disk.
- Analysis of the spatial dynamics and apse precession of TNOs under combined gravitational influences.
Main Results:
- Identified ranges of disk mass, eccentricity, and precession rate that lead to stable, antialigned apse-clustered TNO populations.
- Demonstrated that a massive TNO disk can effectively shepherd eccentric TNOs into stationary configurations.
Conclusions:
- The shepherding disk hypothesis provides a viable explanation for observed TNO orbital clustering.
- This model offers a compelling alternative to the Planet Nine hypothesis, supported by solar system formation theories and observations of exoplanetary disks.
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