The growth rate of the instability of a neutron star with toroidal magnetic fields normalized by the maximum growth rate |σ_max| (left) and corresponding m mode (right) on the meridian plane for nonrotating Newtonian polytrope with ρ₀ = 0.16 and B₀ = 0.2. The white colored region and the dotted curve denote the stable region and critical radius, respectively, and r_s denotes the stellar radius.