The Spectra of CH Stars

Abstract

Five high-velocity carbon stars for which spectra have been taken in the blue region can be termed "CH stars" because of the great strength of the bands of this molecule. The (0, 0) and (1, 1) bands of both the 2~ - 2fl system and the 2~- - 2fl system have been identified in two of the hottest of these stars. These and overlapping fainter bands from higher vibrational levels not yet analyzed in the laboratory probably account for the suppression of most of the atomic lines between X 3883 and X 4430. Of the atomic lines which are visible, the hydrogen lines and those from ionized elements, particularly Sr~, Ba~, and Ti~, are relatively strengthened in HD 76396 and HD 5223, as compared to a KO giant. Low-excitationlines of neutral elements show the greatest weakening. This behavior suggests rather high luminosity for these stars, but the line spectrum is definitely peculiar. Equivalent spectral types of the CH stars range from G5 to K4 if it is assumed that they do not differ greatly in luminosity from the other carbon stars