Abstract The precise determination of the fundamental parameters of stars is crucial for understanding stellar structure and evolution. In this regard, the asteroseismic parameters of solar-like oscillating stars obtained from space telescopes are very useful for determining the mass (M) and radius (R) of single stars using classical scaling relations. These relations still need to be improved. In this study, we develop alternative scaling relations based on reference frequencies (νmin) due to helium ionization zone glitches, specifically for subgiant (SG) stars. We compile main-sequence (MS) and SG MESA models from the literature and derive new scaling relations for stellar R and surface gravity (g) of evolved stars. The expressions for R and g are obtained simultaneously as functions of the large frequency separation, νmin, and metallicity. These new relations allow M and R to be reliably determined only from observational parameters, without the need for detailed stellar modelling. The resulting νmin-based relations are applied to a sample of 31 Kepler SG stars with masses in the range 0.85-1.74 M⊙ and radii between 1.03 and 2.82 R⊙. Using simultaneous solutions, we estimate new mass and radius ranges of 0.89-1.62 M⊙ and 1.04-2.95 R⊙, respectively. The results demonstrate significant improvements in the determination of M and R for evolved Kepler target stars, highlighting the potential of the new scaling relations in asteroseismic analyses.
Alsaç et al. (Thu,) studied this question.