APOGEE-Kepler Cool Dwarf star ages determination

We focus on lower-main-sequence stars, where other age-dating tools become ineffective. Our age distributions are compared to those derived from asteroseismic and giant samples and solar analogs.

We are able to recover gyrochronological ages for old, lower-main-sequence stars, a remarkable improvement over prior work in hotter stars. Under our model assumptions, our ages have a median relative uncertainty of 14%, comparable to the age precision inferred for more massive stars using traditional methods. We investigate trends of Galactic {alpha}-enhancement with age, finding evidence of a detection threshold between the age of the oldest {alpha}-poor stars and that of the bulk {alpha}-rich population.