Theoretical estimation of the efficiency η_rad given by Eq. (21) of the process to convert gravitational energy into radiation as a function of time. For this plot, we assumed a constant and isotropic power-law luminosity of episode 1, L_PL ≈ 1.8 × 10⁵⁰ erg s^-1 ≈ 10^-4M_⊙ s^-1. We computed the values of the efficiency for the binary systems shown in Table 4. For all cases, we obtain the same evolution of the efficiency with time, i.e., the curves overlap. The values of η_rad are always <10%.