Page:The evolution of worlds - Lowell.djvu/27

Rh "The New Star in the Foot of the Serpent." It shone out in the same sudden manner and faded in the same leisurely way.

Since 1860 there have been several such apparitions, and since 1876 it has been possible to study them with the spectroscope, which has immensely increased our knowledge of their constitution. Indeed, this instrument of research has really opened our eyes to what they are. Nova Cygni, in 1876, Nova Aurigæ, in 1892, and Nova Persei, in 1901, besides several others found by Mrs. Fleming on the Arequipa plates, were excellent examples, and all agreed in their main features, showing that novæ constitute a type of stars by themselves, whose appearing in the first place and whose behavior afterwards prove them to have started from like cause and to have pursued parallel lines of development.

As a typical case we may review the history of Nova Aurigæ. On February 1, 1892, an anonymous postcard was received by Dr. Copeland of the Royal Observatory, Edinburgh, that read as follows: "Nova in Aurigæ. In Milky Way, about 2° south of χ Aurigæ, preceding 26 Aurigæ. Fifth magnitude slightly brighter than χ." The observatory staff at once looked for the nova and easily found it with an opera-glass. They then examined it through a prism placed before their 24-inch reflector and found its spectrum. It proved to be that of a "blaze star."