Abstract:
Despite the prevalence of extrasolar worlds, zeroth-order mysteries about their nature persist, such as how they formed and what sets their physical characteristics. Gravitational dynamics are required to decipher these mysteries and nearly every aspect of planetary systems – from orbital architectures, to interiors and atmospheres, as well as primordial formation and evolution processes. Significant progress can be made towards these problems by working at the interface between observational data and dynamical theory. I will present examples of this overarching theme. Specifically, I will show how exoplanets are sculpted by the dynamics of their axial tilts, also called “obliquities”, or the angles between the planets’ spin axes and their orbital axes. Obliquities play a central role in determining the planets’ atmospheric circulation and climate, but they can also strongly enhance the tidal dissipation rate in short-period planets. This effect can explain a wide range of observational mysteries: a pile-up within the orbital architectures of compact extrasolar systems, the rapid tidal decay of an anomalous hot Jupiter system, unusual features in full-phase photometric light curve observations, signatures of radius inflation among sub-Neptune-mass planets, and the existence of sub-Saturn-mass planets with seemingly prohibited interior structures.
Thesis Advisor: Greg Laughlin
