Magnetic field topology and effective radius of Alfvén wings for oblique intrinsic and exterior field orientations. White dotted lines show magnetic field lines and black arrows indicate the magnetic field direction. The field strength is displayed color coded. The boundary, which separates closed field lines starting and ending on the planet from field lines connecting to the star, are displayed as solid white line. The distance of these field lines at larger distance from the planet establishes the effective diameter D_eff of the Alfvén wings.