Deceleration of the disk by the accreting magnetized star in the corotation approximation

Abstract

We study the process of interaction of an accretion disk with the dipole magnetic field of an accreting star within the corotation approximation. Using dynamical accretion picture we calculate the radius at which the gaseous pressure in the disk is balanced by the pressure of the dipole magnetic field of the accreting star and simultaneously the mass accretion rate in the disk is balanced by the rate of plasma diffusion into the stellar magnetic field. We show that the magnetospheric radius calculated under these conditions in a wide range of parameters is significantly smaller than the canonical Alfvén radius realized in the process of spherical accretion.