Page:In the high heavens.djvu/158

Fig. 24.—The Region of the Milky Way about β Cygni. Showing sixty stars.

spectrum of the new star essentially distinct from that of any other star that had been previously observed was the presence of certain bright lines superposed on a spectrum with dark lines of one of the ordinary types. The position of certain of these lines showed that one of the luminous gases must be hydrogen. It is impossible to dissociate the spectroscopic evidence from the circumstances known in connection with this star. The spectroscope showed that