Constraining the Physical and Orbital Parameters of Kepler Systems using Stability Criteria

Exoplanetary systems discovered through the transit method alone have well known planetary radii and periods, but many of the additional parameters such as masses, eccentricities, and mutual inclinations are poorly known. A variety of techniques have been implemented to find tighter constraints on these parameters. To aid in this endeavor, we employed a set of metrics based on recent publications to estimate the long-term orbital stability for a given system. These methods were then applied to all 227 Kepler systems with 3+ transiting planets. Due to the high dimensionality of this problem, multiple simulation runs, each consisting of 10⁴ realizations per system, were performed with various parameter distributions for the physical and orbital parameters of the planets. This in turn allowed us to constrain certain parameters for a particular run and assess how the remaining parameters affect the stability of the system. Ultimately, we found that the ability to place upper limits on parameters such as masses and eccentricities depended on which metric was used and where the line between stable and unstable was drawn. Still it is expected that upper limits can be placed on planetary parameters for dozens of planets using a conservative stability cutoff.