Period échelle diagrams of asymptotic oscillation modes obtained by solving Eq. (9) using the parameters given in Table 1 and considering a weak coupling between the g-mode cavities (q₁ = 10⁻³). These diagrams were obtained by folding the mode periods using either ΔΠ₁ (left panel) or ΔΠ₂ (right panel). The horizontal dashed lines indicate the location of theoretical pure l = 1 p modes. Modes trapped predominantly in the g₁ cavity (I_g1/I > 0.5) are filled in red, and modes trapped mainly in the g₂ cavity (I_g2/I > 0.5) are filled in blue (mode trapping is estimated based on ratios of inertia, see Sect. 3.5). Other modes are left blank.