Top panel: Contour plot showing the critical period (P_crit) as a function of primary mass (M₁) and surface gravity (log(g)) for systems with i = 60° and q = 0.5. Dashed white contour lines highlight selected P_crit values (1, 2, 5, and 10 days). Bottom Panel: As the top panel, this time displaying the corresponding change in RV (ΔRV_max) computed at P_crit. Dashed white curves mark the contours where ΔRV_max = 20 km s⁻¹ at different inclinations and q = 0.1.