Magnetic energy density radial distribution, shown as a blue solid line. Radial dependence of the combined effects of centrifugal, gravitational, and thermal energy densities shown as red solid lines. The vertical solid line locates the radial distance, where the blue and red lines intersect. Stellar parameters refer to the reference star, which has stellar parameters where the distributions peak (T_eff = 13 kK; R_* = 2.7 R_⊙; M_* = 3.2 M_⊙; B_p = 3.1 kG; P_rot = 1.1 d). The thermal plasma pressure, evaluated under isobaric conditions, is marked by the horizontal dashed line. The vertical dotted line marks the position of the Kepler radius. Different cases of plasma density and the surface and exponent of the corresponding radial density law have been considered.