The Stars of High Luminosity

abnormally absolute magnitude absorption O stars apparent magnitude atmospheres bolometric bright lines brighter c-character c-stars calcium Cepheid variables Chapter XIV cluster type variables color contour Contr Cygni discussed dispersion dwarf emission lines fainter G band Gerasimovič giant hazy helium Henry Draper Henry Draper Catalogue high luminosity stars hydrogen lines intensities ionization K line light curves line depth Lines appear narrow Lines narrow Lines Lines somewhat narrow Lines very narrow log NH long period variables luminous Maury division maximum measured Messier Miss Cannon Mount Wilson narrow Lines narrow nebulae normal stars novae number of stars numbers of atoms observed percentage light losses pressure radial velocity range ratio Shapley and Miss similar spectral class spectral sequence spectroscopic binary stars of Class stellar summarized supergiant surface gravity Table VIII Table XV theory total absorption Unsöld variable stars visual magnitude Wolf-Rayet stars Ηγ ΙΟ