Turbulent magnetic decay τ_t (49) of fossil fields, normalised by laminar Ohmic timescale τ_Ω ∼ (Ω_s Ek/Pm)⁻¹, as a function of equatorial ellipticity β₀ and dimensionless orbital angular frequency Ω₀ = Ω_orb/Ω_s. Non-magnetic close binaries are illustrated by the symbols given in Table 2. Large (white) symbols refer to body 1 of the considered binary, whereas small (cyan) symbols refer to body 2. Computations at Ek/Pm = 10⁻¹² and K_α = 30.