2:00–3:00 pm ERC 401
Nora Bailey "Planet-Planet Interactions in Exoplanet Systems"
The gravitational interactions of planets in multiplanetary systems can have effects ranging from tiny orbital alterations to severe instability and everything in between. In this talk, I will discuss three applications of planet-planet interactions. First, I investigate a commonly used analytical approximation and its shortcomings when applied to planetary systems like those observed by the Kepler mission when used to calculate the rate at which the longitude of the ascending node changes. Secondly, I illustrate how the slight change in period ratio over time for planet pairs both in and out of mean-motion resonance can lead to observable sculpting of the time-averaged period ratio for a population of planets and how the strength of this sculpting depends on the eccentricity of the planets involved. Lastly, I endeavor to quantify how the presence of two giant planets affects the potential habitability of an Earth-like planet. I assess the relative habitability for each giant planet configuration---that is, the integrated habitability probability compared to a system with only an Earth-like planet. By varying the properties of the two giant planets (mass, semi-major axis, eccentricity, and inclination), I identify correlations between various parameters, identify particularly habitable and uninhabitable configurations, and demonstrate how the interplay of mean-motion resonance, secular resonances, and other dynamical effects must be taken into account when considering habitability.
