The past decade has delivered remarkable discoveries in the study of exoplanets. Hand-in-hand with these advances, a theoretical understanding of the myriad of processes that dictate the formation and evolution of planets has matured, spurred on by the avalanche of unexpected discoveries. Appreciation of the factors that make a planet hospitable to life has grown in sophistication, as has understanding of the context for biosignatures, the remotely detectable aspects of a planet's atmosphere or surface that reveal the presence of life. Exoplanet Science Strategy highlights strategic priorities for large, coordinated efforts that will support the scientific goals of the broad exoplanet science community. This report outlines a strategic plan that will answer lingering questions through a combination of large, ambitious community-supported efforts and support for diverse, creative, community-driven investigator research.

Exoplanet research is one of the most explosive subjects in astronomy today. More than 500 exoplanets are now known, and groups world-wide are actively involved in a broad range of observational and theoretical efforts. This book ties together these many avenues of investigation - from the perspectives of observation, technology and theory - to give a comprehensive, up-to-date review of the entire field. All areas of exoplanet investigation are covered, making it a unique and valuable guide for researchers in astronomy and planetary science, including those new to the field. It treats the many different techniques now available for exoplanet detection and characterisation, the broad range of underlying physics, the overlap with related topics in solar system and Earth sciences, and the concepts underpinning future developments. It emphasises the interconnection between the various fields and provides extensive references to more in-depth treatments and reviews.

An extrasolar planet discovered around one of the brightest stars in the sky would be a prime target for follow-on observing and characterization, especially if the planet were within the star's habitable-zone. The brightest stars are, however, often not considered to be practical targets for photometric planetary transit searches, despite the scientific rewards that finding a planet around these stars would provide. Exo-PlanetSat is a proposed satellite constellation that will survey the brightest G- and K-dwarfs across the entire sky and look for transits of Earth-sized planets in the habitable-zone. By using measurements of stellar orientations provided primarily by asteroseismic observations, only those stars whose axes lie near 900 to our line of sight will be observed. This increases the transit probability of a habitable-zone planet from 0.5% to 5%, lowering the number of stars that need to be examined by a factor of ten. This in turn enables the design of a practical survey of the brightest stars. A proposed concept of operations envisions thirty small spacecraft in low Earth-orbit, each individually targeted onto a bright star. Over the course of four years, these spacecraft will able to observe a sufficient number of solar-like stars to expect the detection of three habitable-zone Earths with high statistical confidence, assuming that every star has such a planet in orbit.

The methods used in the detection and characterisation of exoplanets are presented in this unique textbook for advanced undergraduates.

The following dissertation presents work done as part of a ground-based transit follow-up program designed to look for transit timing variations in well-known transiting systems called, the Apache Point Survey of Transit Lightcurves of Exoplanets (APOSTLE). I outline the observing strategy, data reduction and analysis of data for the objects GJ 1214b, XO-2b and TrES-3b. The results of our analysis show general agreement with previously measured properties for these systems, and in some cases we are able to place tighter constraints on system parameters. We were able to detect a low-energy stellar flare, and three spot-crossing events with our observations of GJ 1214b. Our transit timing data do not show strong signs of timing variations and hence we are unable to claim detections of additional planets. Even though the results of this study do not present any new discoveries, the topics outlined in this dissertation are a useful synthesis of techniques used to execute a high-precision ground-based transit follow-up project.