HR Diagrams Derived from the Michigan Spectral Catalogue

Abstract

In this paper we present some HR diagrams constructed using data from theMichigan Spectral Catalogues. Houk (1975) has been systematically reclassifying the Henry Draper stars on the MK system, from the south pole northward. Objective-prism plates, with a reciprocal dispersion of 108 Å/mm, have been taken with the Michigan Curtis Schmidt telescope at Cerro Tololo Inter-American Observatory in Chile. The spectra are classified visually from the plates, and the results are put onto IBM cards and magnetic tape from which the catalogues are produced.