Warm, Large Exoplanets

Extra-solar planetary systems have surprised us with their dramatic differences from planets in our Solar System. Among the most mysterious in origin are planets with orbital periods 10-200 days and sizes larger than Neptune's. Such Warm, Large Exoplanets (WaLEs) have been more easily discovered than their smaller and/or longer-period counterparts, yet they are challenging to account for theoretically. Their large atmospheres, short orbital periods, and large ranges of mass and eccentricity have posed a puzzle to theories of how planetary systems form and evolve. WaLEs are the easiest planets to characterize apart from hot Jupiters but have been studied in much less detail, making them ripe for first order discoveries. The Kepler Mission discovered a rich sample of approximately 90 WaLE candidates that have not yet been studied systematically. Furthermore, WaLEs will be readily discovered by the {Transiting Exoplanet Survey Satellite (TESS)} and are prime targets for atmospheric characterization by the {James Webb Space Telescope (JWST)}. Therefore now is a critical time for a detailed population study of WaLEs to establish the context of their properties and origins. We propose to investigate through the following avenues:

1. Simulations of the dynamical and tidal evolution of planetary systems that can transform planets formed at larger separations into WaLEs. We will specifically conduct a parameter study of a mechanism -- a flavor of Kozai-Lidov oscillations with tidal friction that involves a nearby, eccentric, mutually inclined planetary perturber -- demonstrated to be promising for producing the population of WaLEs on elliptical orbits discovered by radial-velocity (RV) surveys.

2. Using data from the Kepler Mission, constrain the eccentricities, transit timing variations, and transit duration variations of WaLEs, cataloguing both detections and upper-limits. Place limits on eccentric warm Jupiters' perturbers using published radial-velocity data. We will then compare to the predictions generated by our parameter study to test the mechanism above.

3. Use our resulting catalogue to assess architectures, orbital properties, and stellar properties as a function of planet size, determining whether a dependence on the WaLE's size is evident.