Page:The Music of the Spheres.djvu/136

 3rd magnitude star, Albireo, is a favorite with amateur astronomers, for it has a 5th magnitude companion star of the richest and most vivid greenish-blue. This lovely double star with its sharply contrasted colors may be seen to good advantage in a small telescope and vies in beauty with the famous three-colored star, Gamma Andromedæ.

Deneb, the brilliant white star at the head of the Cross, is a very distant sun but is so large that it shines forth brightly among our finest stars. It is estimated by astronomers as being at a much greater distance than the Harp Star, Vega, and Vega is distant about 232 millions of millions of miles!

In contrast to the huge sun that Deneb must be to shine so brightly at its great distance, there is a little star above the armpiece on the eastern side of the Cross, which is the nearest star to the earth that has yet been found, as seen from the northern hemisphere. This faint star is really a very tiny sun for nine more similar suns thrown into it and blazing as one big fire, would no more than equal our sun in brilliancy.

In the vicinity of 61 Cygni, is a large, mysterious, black spot visible on account of the glow of light from the densely packed stars of the Milky Way. This spot was first described as being "like a hole" and was curiously named "A Sack of Coals." Science later suggested that since we have dark suns perhaps we also have dark nebulæ and that such an object may be lying between us and those distant stars. The late E. E. Barnard of Yerkes Observatory made extensive studies of the distribution of nebular matter and he seems to have definitely proved the existence of "dark nebulæ." The black spots and "rifts" in the