Masses and ages of red giants

This is qualitatively expected from mass-dependent post-main-sequence evolution. We here establish an empirical relation between these quantities by drawing on 1475 red giants with asteroseismic mass estimates from Kepler that also have spectroscopic labels from Apache Point Observatory Galactic Evolution Experiment (APOGEE) DR12.

We assess the accuracy of our model, and find that it predicts stellar masses with fractional rms errors of about 14 percent (typically 0.2M_{sun}_). From these masses, we derive ages with rms errors of 40 percent. This empirical model allows us for the first time to make age determinations (in the range 1-13Gyr) for vast numbers of giant stars across the Galaxy.