Theses

During its prime mission, the Kepler Space Telescope found over 700 systems with more than one transiting planet. These multiple planet systems (multis) are the most information rich and dynamically interesting of all exoplanets. We picked 46 multis where one planet was experiencing transit timing variations (TTVs) not obviously caused by the other known planets. TTVs are caused by interactions between planets and therefore can provide evidence of additional, hidden planets in these systems. We first tried to determine if the TTVs could be reasonably explained by the known planets. We then projected six possible hidden planets for each system and performed the same analysis on the hidden planet in the strongest resonance with the TTV-experiencing planet that was estimated to be stable. Five of our systems have good fits with the known planets, 39 have good fits with the hidden planet added, and two require more work to find a satisfactory answer. This work significantly improves our understanding of the architectures of some of the most interesting multis from Kepler.

During the Kepler Space Telescope's 9-year mission, it discovered over 2,300 planets around other stars but could not document information about the angle between the orbital planes of planets in the same stellar system. As scientists have examined the Kepler data, these angles between exoplanetary orbits, termed mutual inclinations, have been largely overlooked because they typically cannot be fully inferred, even though they provide valuable insight into the formation and evolution of planetary systems. Mutual inclinations for the entire Kepler population have been estimated by a variety of researchers, but there are still many questions about whether or how the mutual inclination distribution depends on the system architecture. We are exploring what mutual inclination information can be derived from light curves of individual Kepler systems of multiple transiting planets. The strongest information comes from the ~26 systems with clear Transit Duration Variations (TDVs)–variations in the length of time a planet passes in front of its star–which likely come as the result of detectable nodal precession due to mutual gravitational interactions (Kane et al. 2019). Our photodynamical model, PhoDyMM, has been used to explicitly study mutual inclinations on unusual systems before, but most light curves are studied by fixing all longitudes of the ascending nodes to zero by default. Our project uses synthetic light curves of systems we create with known solutions to determine the accuracy and precision of our methods in determining mutual inclinations. Using synthetic light curves, we assess PhoDyMM’s ability to correctly infer mutual inclinations (and other parameters) under a variety of model assumptions and find it to be efficient and accurate. We will also present investigations of the Kepler-18 system.

The triple system 47171 Lempo (1999 TC36) is very unique in the Kuiper Belt (a collection of small, icy objects past the orbit of Neptune) and in the solar system: it consists of a close-proximity binary orbited by a single moon. The two bodies of the binary have nearly identical mass. Because of the unique configuration of the system, especially the close proximity of the inner binary, the orbits are complicated and cannot be modeled using Keplerian dynamics. Dr. Simon Porter of the Southwest Research Institute developed an integrator, called SPINNY (SPIN+N-bodY), in order to produce numerical solutions to the orbits of multi-body systems. I also designed several tests in order to evaluate the accuracy of SPINNY’s models. The specifics of these tests and their results are discussed in this paper.