Graduation Semester and Year

2021

Language

English

Document Type

Thesis

Degree Name

Master of Science in Physics

Department

Physics

First Advisor

Nevin Weinberg

Abstract

Short period planets tidally excite internal gravity modes within their host star. These excited modes, known collectively as the dynamical tide, dissipate orbital energy and cause the planet’s orbit to decay. In hot Jupiter systems, resonantly excited gmodes are driven to such large amplitudes in the stellar core that they nonlinearly excite a sea of secondary modes. These secondary modes can greatly enhance the efficiency of tidal dissipation compared to linear theory predictions and thus significantly increase the rate of orbital decay. In this thesis we calculate the three-mode coupling coefficients between the excited g-modes of hot Jupiter host stars. These coefficients determine the strength of the nonlinear mode interactions and are thus a crucial quantity needed to determine the rate of nonlinear tidal dissipation. Previous studies only calculated the coupling coefficient in solar-type host stars even though hot Jupiters are observed to orbit a wide range of stellar types. We calculate the coupling coefficients for low- and high-mass main sequence stars that correspond to the full range of observed hot Jupiter hosts (from 0.6 ��⊙ to 1.6 ��⊙). We find that the coupling coefficient is sensitive to the mass and age of the host star, suggesting that some hot Jupiter systems are much more prone to orbital decay than others.

Keywords

Physics, Astrophysics, Astronomy, Exoplanets, Extrasolar planets, Hot Jupiters, Solar type, Non-solar type, G modes, Seismology, Tides, Dynamical tides, Resonance, Coupling coefficient, Nonlinear coupling coefficient, Mesa, Gyre, Solar mass, Lower mass, Higher mass

Disciplines

Physical Sciences and Mathematics | Physics

Comments

Degree granted by The University of Texas at Arlington

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