Award Date

8-1-2017

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Physics and Astronomy

First Committee Member

Rebecca Martin

Second Committee Member

Stephen Lepp

Third Committee Member

George Rhee

Fourth Committee Member

Arya Udry

Number of Pages

68

Abstract

We investigate gravitational perturbations of an asteroid belt by secular resonances. We ap- ply analytic and numerical models to main–sequence and post–main–sequence planetary systems. First, we investigate how the asteroid impact rate on the Earth is affected by the architecture of the planetary system. We find that the nu6 resonance plays an important role in the asteroid collision rate with the Earth. Compared to exoplanetary systems, the solar system is somewhat special in its lack of a super–Earth mass planet in the inner solar system. We therefore consider the effects of the presence of a super–Earth in the terrestrial planet region. We find a significant effect for super–Earths with a mass of around 10 M_{Earth} and a separation greater than about 0.7 AU. These results have implications for the habitability of exoplanetary systems. Secondly, we model white dwarf pollution by asteroids from secular resonances. In the past few decades, observations have revealed signatures of metals polluting the atmospheres of white dwarfs that require a continu- ous accretion of asteroids. We show that secular resonances driven by two outer companions can provide a source of pollution if an inner terrestrial planet is engulfed during the red-giant branch phase. Secular resonances may be a viable mechanism for the pollution of white dwarfs in a variety of exoplanetary system architectures including systems with two giant planets and systems with one giant planet and a binary star companion.

Keywords

asteroids: general; minor planets; planets and satellites:dynamical evolution and stability; stars: AGB and post-AGB; stars: white dwarfs

Disciplines

Astrophysics and Astronomy

Language

English


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