Rigid rotators. a) Iso-density surfaces in model stars of M = 5   M_⊙ in the ZAMS rotating at a₁) Ω = 0; a₂) Ω = 0.85Ω_c; a₃) Ω = Ω_c = 1.92 × 10^-4 s^-1; b) Iso-density surfaces in stars of M = 5   M_⊙ in the TAMS rotating at b₁) Ω = 0; b₂) Ω = 0.85Ω_c; b₃) Ω = Ω_c = 4.79 × 10^-5 s^-1.The iso-density surfaces are labeled with the corresponding density ratios ρ/ρ_c, which are the same in all panels of the figure.