Potsdam Empirical Rotational Isochrones from CLustEr Stars (PERICLES)

Isochrones, equal-age curves, are widely used in astrophysics to estimate stellar ages.
Classical stellar parameters are, however, very limited in their usability for main sequence
stars because of their weak age-dependence. Here, rotation period measurements provide
complementary information. We construct and present a set of rotational isochrones, named
the Potsdam Empirical Rotational Isochrones from CLustEr Stars (PERICLES), that leverage
rotation periods. They are constructed empirically using stars in well-studied open clusters
and a small number of complementary field stars. The rotational isochrones span the main
sequence stars from late-F type near the Kraft break to the fully-convective boundary around
M3 stars, and are available for ages = 6 Gyr. We also discuss a limitation to such color- or
temperature based rotational isochrones, together with ideas to overcome it.