  The catalog of stellar evolution tracks discussed in our previous work is
meant to help characterize exoplanet host-stars of interest for follow-up
observations with future missions like JWST. However, the utility of the
catalog has been predicated on the assumption that we would precisely know the
age of the particular host-star in question; in reality, it is unlikely that we
will be able to accurately estimate the age of a given system. Stellar age is
relatively straightforward to calculate for stellar clusters, but it is
difficult to accurately measure the age of an individual star to high
precision. Unfortunately, this is the kind of information we should consider as
we attempt to constrain the long-term habitability potential of a given
planetary system of interest. This is ultimately why we must rely on
predictions of accurate stellar evolution models, as well a consideration of
what we can observably measure (stellar mass, composition, orbital radius of an
exoplanet) in order to create a statistical framework wherein we can identify
the best candidate systems for follow-up characterization. In this paper we
discuss a statistical approach to constrain long-term planetary habitability by
evaluating the likelihood that at a given time of observation, a star would
have a planet in the 2 Gy continuously habitable zone (CHZ2). Additionally, we
will discuss how we can use existing observational data (i.e. data assembled in
the Hypatia catalog and the Kepler exoplanet host star database) for a robust
comparison to the catalog of theoretical stellar models.
