Fundamental stellar parameters and age–metallicity relation of Kepler red giants in comparison with theoretical evolutionary tracks

Spectroscopic parameters (effective temperature, metallicity, etc) were determined for a large sample of ∼100 red giants in the Kepler field, for which mass, radius, and evolutionary status had already been asteroseismologically established. These two kinds of spectroscopic and seismic information suffice to define the position on the ‘luminosity versus effective temperature’ diagram and to assign...