Consistency of isochronal ages and asteroseismic ages

Determine whether ages inferred from isochrone fitting to colour–magnitude diagrams using stellar surface parameters are consistent with ages inferred from asteroseismic diagnostics of stellar interiors, such as gravity‑mode period‑spacing and near‑core rotation measurements, in stellar populations.

Background

Isochrone fitting is a standard method to estimate the ages of stellar populations, but the resulting ages are sensitive to the adopted input physics, including convective‑core overshoot, rotation, and extinction. Different model families (e.g., PARSEC versus MIST) can yield discrepant ages, particularly around the extended main‑sequence turn-off.

Asteroseismology provides complementary age diagnostics based on stellar interior properties, especially via gravity‑mode period‑spacing patterns that constrain near‑core structure and rotation. The paper investigates NGC 6866 using Gaia photometry and Kepler asteroseismology, motivated by the unresolved issue of whether ages derived from surface‑based isochrones agree with ages derived from interior asteroseismic constraints.