Photodetachment of electrons compounded to excited hydrogen atoms as source of absorption features in magnetic stars?

Scattering of thermal electrons at excited hydrogen atoms forms resonances, from which absorption features may arise, if the resonances do not decay by electron emission before; these absorption features agree in wavelengths with those observed in normal early type stars (Teff ∼ 104 K) and predominantly in magnetic stars. It is shown that the conditions for the formation of the resonances, the quasistable states of H-, are just most convenient for the stars in question. (author)