Propagation diagrams showing the mode cavities, frequencies and nodes of the theoretical period-spacing pattern of our overall best model (M = 1.65 M_⊙, X_c = 0.24, f_ov = 0.005, and log D_mix = 1.5). The thick solid, dashed and dotted curves represent the Brunt–Väisälä frequency (N), and the ℓ = 1 and ℓ = 2 Lamb frequencies (S_ℓ = 1 and S_ℓ = 2) respectively. The red region represents the ℓ = 1 g mode cavity that gets extended by the pink region for the ℓ = 2 g-modes. The blue region represents the ℓ = 2 p-mode cavity that gets extended by the light blue region for the ℓ = 1 p modes. The horizontal black and grey dotted lines represent the 20 ℓ = 1 and 11 ℓ = 2 theoretical frequencies, with the nodes of radial Lagrangian displacement vector for each frequency represented by black circles and grey triangles respectively. Right panel: magnification of the frequency region in which the theoretical modes propagate.