Revised MK Spectral Classification of the Red Carbon Stars

The spectral classification of the red carbon stars has been brought into the revised MK system by combining some of the features of the old R, N, and classifications, as modified by Yamashita, and adding numerical abundance indices. The new types are intended to (1) define the population to which the star belongs, (2) allow quick interpolation between the detailed atmospheric analyses of individual stars, and (3) indicate the differences between carbon stars in different parts of our galaxy, and in other galaxies. It is the flexibility of the notation, allowing the incorporation of improved criteria, that should make the new system useful.