In this Day and Age: An Empirical Gyrochronology Relation for Partially and Fully Convective Single Field Stars

Abstract: Gyrochronology, the field of age-dating stars using mainly their rotation periods and masses, is ideal for inferring the ages of individual main-sequence stars. However, due to the lack of physical understanding of the complex magnetic fields in stars, gyrochronology relies heavily on empirical calibrations that require consistent and reliable stellar age measurements across a wide range of periods and masses. In this paper, we obtain a sample of consistent ages using the gyro-kinematic age-dating method, a technique to calculate the kinematics ages of stars. Using a Gaussian Process model conditioned on ages from this sample (~ 1 - 14 Gyr) and known clusters (0.67 - 3.8 Gyr), we calibrate the first empirical gyrochronology relation that is capable of inferring ages for single, main-sequence stars between 0.67 Gyr to 14 Gyr. Cross-validating and testing results suggest our model can infer cluster and asteroseismic ages with an average uncertainty of just over 1 Gyr. With this model, we obtain gyrochronology ages for ~ 100,000 stars within 1.5 kpc of the Sun with period measurements from Kepler and ZTF, and 384 unique planet host stars.