Common Age and Initial Metallicity for the 16 Cyg Binary System

Solar-like oscillating binary systems provide powerful constraints on stellar evolution, as their components are expected to share the same initial chemical composition and age due to their common origin. Asteroseismology further allows these parameters to be determined with high precision. The 16 Cyg system, whose components are both solar analogues and show solar-like oscillations, represents an excellent laboratory in this context. In this study, we constructed stellar models of 16 Cyg A and B using the MESA evolutionary code under the spectroscopic and interferometric constraints. We found a common age of t ≈ 8.0 Gyr for an initial metallicity of Z0 = 0.0166. The masses of the components are MA = 1.000 M⊙ and MB = 0.971 M⊙. The models agree well with the interferometric radii, observed effective temperatures, and luminosities. The surface metallicities are Zs = 0.01390 and Zs = 0.01404 for 16 Cyg A and B, respectively, showing consistency with the expected effects of microscopic diffusion.