Until the 1990s, the only known planets were those in our Solar System. Three decades later, several thousand exoplanets have been discovered orbiting stars other than the Sun, and substantial... Show moreUntil the 1990s, the only known planets were those in our Solar System. Three decades later, several thousand exoplanets have been discovered orbiting stars other than the Sun, and substantial efforts have been made to explore these strange new worlds through spectroscopic analyses of their atmospheres. In particular, high-dispersion spectroscopy has provided robust measurements of these objects, enabling investigations of the significant, outstanding questions of exoplanetary science: What kinds of planets exist beyond our Solar System? Of what are they made? How did they form? Is there life beyond Earth? This dissertation touches upon all of these topics. Chapter 2 details a study to understand the chemical composition of one of the most extreme exoplanets. Chapter 3 investigates the feasibility of studying the different isotopes of titanium in large gaseous exoplanets, which may provide insight into their formation. Chapter 4 presents an attempt to detect young, still-forming planets in an effort to better understand how this process works. Chapter 5 concludes this dissertation with an evaluation of the ability of large future telescopes to detect molecular oxygen in Earth-like exoplanets, which may trace the presence of life. Show less
