Pressure amplitude on a meridian plane for a polytropic stellar model, with d the distance to the rotation axis and ρ₀ the equilibrium density. The mode shown corresponds to n = 50, ℓ = 1 and m = 1 at a rotation rate of Ω/Ω_K = 0.300, where is the limiting rotation rate for which the centrifugal acceleration equals the gravity at the equator, M being the stellar mass and R_eq the equatorial radius. Colors/grayness (for respectively the colour/black and white version of the figure) denote pressure amplitude, from red/gray (maximum positive value) to blue/black (minimum negative value) through white (null value). The thick black line is the ray γ located in the center of the main stable island. (This figure is available in color in the electronic form.)