Estimate of the relative error between the oscillation period of the neutrino signal in model s25 in Müller & Janka (2014) and in analytical estimates. The empirical formula (32) is shown with a purple line. The result of the perturbative calculation is shown for r_∇ = r_ns without dissociation (orange line, Eq. (33)), and for r_∇ = 1.3r_ns with dissociation prescribed by Eq. (35) (green line, Eq. (36)). The sensitivity to the estimate of r_∇ is shown with dashed lines for r_∇ = 1.25r_ns (khaki) and r_∇ = 1.35r_ns (blue).