Page:Popular Science Monthly Volume 11.djvu/74

64 on December 1st, as to Schmidt on November 24th, it appeared to be of from the third to the fourth magnitude; on December 3d it had fallen to the fourth magnitude, and on December 4th to the fifth magnitude. The right ascension was 24h 36m 50.4s; declination, +42° 16' 37.7" for 1886. O.



We may observe here that there is nothing in common between this new star and those which made their appearance in 1600 in the neck of the Swan, and in 1670 near β of the same constellation. The only point of agreement between them is their nearness to the Milky-Way.

In comparing Schmidt's observations with those of Prosper Henry, we note two important facts: the first is, the diminution of lustre, varying in eight days from the third to the fifth magnitude; and, second, the notable change of color, from a pronounced yellow to greenish blue—a change so patent that it cannot be referred to individual differences of judgment, or to atmospheric influences.

The new star of the Swan has been made the subject of a very interesting spectroscopical study. As early as December 2d, Cornu applied a spectroscope to the great equatorial in the eastern tower of the Paris Observatory. Cazin, too, employed for the same purpose the nine-inch equatorial telescope (the object-glass of which is by Leon Foucault). Both of these observers arrived at the same conclusion. The spectrum of the star, observed during a brief interval of clear sky, appeared to "consist in great part of bright lines, and hence