The Perkins Catalog of Revised MK Types for the Cooler Stars (original) (raw)

Abstract

A catalog is presented listing the spectral types of the G, K, M, and S stars that have been classified at the Perkins Observatory in the revised MK system. Extensive comparisons have been made to ensure consistency between the MK spectral types of stars in the Northern and Southern Hemispheres. Different classification spectrograms have been gradually improved in spite of some inherent limitations. In the catalog, the full subclasses used are the following: G0, G5, G8, K0, K1, K2, K3, K4, K5, M0, M1, M2, M3, M4, M5, M6, M7, and M8. The irregularities are the price paid for keeping the general scheme of the original Henry Draper classification.