Influence of companion composition on evaporation timescale. The contours of t_ev = 10⁶yr (solid lines) and t_ev = 10¹² yr (dashed lines) are represented as a function of companion distance a and size R for P = 10 ms, B = 10⁸ G, and an indicative (and conservative) density ρ = 1 g cm^-3, and for various companion refractive indices as indicated in the legend (increasing from right to left): σμ = 10⁴⁻¹⁴ s^-1, corresponding to N_r = 10¹⁻⁶.