Status Report

Planetary chaotic zone clearing: destinations and timescales

By SpaceRef Editor
November 6, 2014
Filed under , , ,

Sarah Morrison, Renu Malhotra

(Submitted on 5 Nov 2014)

We investigate the orbital evolution of particles in a planet’s chaotic zone to determine their final destinations and their timescales of clearing. There are four possible final states of chaotic particles: collision with the planet, collision with the star, escape, or bounded but non-collision orbits. In our investigations, within the framework of the planar circular restricted three body problem for planet-star mass ratio μ in the range 10 −9 to 10 −1.5 , we find no particles hitting the star. The relative frequencies of escape and collision with the planet are not scale-free, as they depend upon the size of the planet. For planet radius R p ≥0.001 R H where R H is the planet’s Hill radius, we find that most chaotic zone particles collide with the planet for μ? 10 −5 ; particle scattering to large distances is significant only for higher mass planets. For fixed ratio R p / R H, the particle clearing timescale, T cl , has a broken power-law dependence on μ . A shallower power-law, T cl ∼ μ −1/3 , prevails at small μ where particles are cleared primarily by collisions with the planet; a steeper power law, T cl ∼ μ −3/2 , prevails at larger μ where scattering dominates the particle loss. In the limit of vanishing planet radius, we find T cl ≈0.024 μ − 3 2. The interior and exterior boundaries of the annular zone in which chaotic particles are cleared are increasingly asymmetric about the planet’s orbit for larger planet masses; the inner boundary coincides well with the classical first order resonance overlap zone, Δ a cl,int ?1.2 μ 0.28 a p ; the outer boundary is better described by Δ a cl,ext ?1.7 μ 0.31 a p , where a p

is the planet-star separation.

Comments: 20 pages, 7 figures; accepted for publication in ApJ

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

Cite as: arXiv:1411.1378 [astro-ph.EP] (or arXiv:1411.1378v1 [astro-ph.EP] for this version)

Submission history

From: Renu Malhotra 

[v1] Wed, 5 Nov 2014 19:50:33 GMT (241kb)

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