Electric fields, accretion, and stellar winds in helium-rich atmospheres.

We suggest that the electric fields of stellar atmospheres play an essential role in the accretion and mass ejection processes, especially of He-rich stars. The static configuration implies an electric field that is strong enough to push protons outward, but sufficiently weak to enable as many electrons as protons to escape. This process can stop hydrogen accretion on white dwarfs and may thus explain the existence of He-rich white-dwarf atmospheres in an H-rich environment. However, a hot corona must be postulated. It also gives the driving force needed for the stellar wind which is probably necessary to explain the He-rich main-sequence stars. At the same time, a pure helium white dwarf need not be created with no hydrogen. Any remaining hydrogen will be expelled.It is found that the behavior of the electric field close to the star requires further study.