Gyrochronology Model Evaluation Method

Accurate stellar ages are essential for our understanding of the star formation history of the Milky Way, Galactic chemical evolution, and to constrain exoplanet formation models. Gyrochronology, an empirical relationship between stellar rotation and age, appears to be a reliable age indicator for main sequence stars over the mass range 0.6 to 1.0 M. Under the assumption that wide binaries contain two coeval stars, we selected pairs from the Kepler, K2, and T ESS surveys in order to evaluate three Gyrochronology models (Barnes 2007; Angus et al. 2015; Mamajek & Hillenbrand 2008). In this first paper in a planned series, we describe a Monte Carlo approach to assess the precision and accuracy of age derived from these models. We use this technique to demonstrate that current gyrochronology models achieve ∼25 % precision in ages when σP /P = 0.1 and σB−V = 0.02. We also outline ways to improve this to ∼10 %