Discrete eigenstates of the He+ ion moving in a strong magnetic field

We present precise results for the binding energies and sizes of the He+ ion moving across a strong pulsar-type magnetic field. Similarly to the previously studied case of hydrogen, the ion is strongly deformed by the action of the motion-induced Stark fords. Unlike the case of the neutral hydrogen atom whose transverse motion gives rise-for every discrete state of the nonmoving atom-to a continuum of displaced energy states with changing transverse momentum, transverse motion of the Het ion gives rise to a discretely spaced energy spectrum. A quantitative understanding of this problem and related opacities is central in modeling neutron star atmospheres, and should help in the interpretation of thermal emission from radio pulsars.