Estimates of the magnetospheric radius published in the literature (black points, see text for references) and obtained in this work (red circle) as a function of luminosity. Theoretical estimates of the magnetospheric radii for dipole R_m, dip, assuming ξ = 0.49 and μ₃₀ = 0.43 (Campana et al. 2018), and quadrupole R_m, quad with ξ = 0.8 and μ₃₀ = 0.43 (Mönkkönen et al. 2019), corotation radius R_c and estimated luminosities for the propeller transition obtained in this work and by Campana et al. (2018; black dotted lines) are also shown.