The classification of helium-rich hot subdwarfs

C.S.Jeffery, J.S.Drilling, P.M.Harrison, U.Heber, S.Moehler

We introduce a spectral classification system for helium-rich hot subdwarfs based on 1.5 Angstrom spectra of high S/N. Based on a small number of absorption line ratios, the scheme is logically constructed and can be extended to similar spectra of all hot subdwarfs.