Track of a 1 M_⊙ star with solar metallicity showing the coupling coefficient q as a function of ν_max. Yellow points indicate strong coupling, cyan points indicate weak coupling. Observed coupling and Δν (Vrard et al. 2016; Mosser et al. 2017) in stars with masses between 0.9 M_⊙ and 1.1 M_⊙ and metallicities between −0.070 and 0.180 are shown as black dots and squares, with dots having ΔΠ₁ ≤ 130 s and squares ΔΠ₁ > 130 s. The red points show the locations of models A–D.