  A conducting disk significantly changes the generation of the electromagnetic
radiation excited by the rotation of the magnetic field frozen to a star. Due
to the reflection of waves from a disk there appear waves propagating toward a
star, not only outward a star as it takes place for the magneto-dipole
radiation. Because that the angular momentum can be transformed from a disk to
a star when the inner edge of a disk approaches the light surface of a rotating
star. This is purely electromagnetic effect. At some distance of a disk from a
star, $r_d=r^*\simeq c/\omega_s$, the stellar angular momentum losses due to
the electromagnetic radiation become zero. It results the stable stellar
rotation.
