Family of solutions for the mass m₃, orbital period P_b, 3, and relative distance R for a second companion of NGC 1851A using the limits on all the frequency derivatives mentioned in the text. The different eccentricities are shown in different colours. The constant lines of ${\dot{\omega }}_{\mathrm{tidal}}/{\dot{\omega }}_{\mathrm{obs}}$ are shown with dotted black lines in the bottom plot, while the dash-dotted crimson lines indicate constant ẋ_tidal.