and twenty-three hours,
but the actual changes occupy only about ten hours, and it loses light
more swiftly than it regains it. A combination of red and blue is
presented by Phi (mistakenly marked on map No. 23 as psi). The
magnitudes are six and eight, distance 56", p. 242 deg.. A double of similar
magnitudes is chi, distance 19", p. 25 deg.. Between the two stars which the
naked eye sees in kappa is a minute pair, each of less than the eleventh
magnitude, distance 5", p. 324 deg.. Another naked-eye double is formed by
theta^1 and theta^2, in the Hyades. The magnitudes are five and five and
a half, distance about 5' 37".

The leading star of Taurus, Aldebaran (alpha), is celebrated for its
reddish color. The precise hue is rather uncertain, but Aldebaran is not
orange as Betelgeuse in Orion is, and no correct eye can for an instant
confuse the colors of these two stars, although many persons seem to be
unable to detect the very plain difference between them in this respect.
Aldebaran has been called "rose-red," and it would be an interesting
occupation for an amateur to determine, with the aid of some proper
color scale, the precise hue of this star, and of the many other stars
which exhibit chromatic idiosyncrasy. Aldebaran is further interesting
as being a standard first-magnitude star. With the four-inch glass we
see without difficulty the tenth-magnitude companion following Aldebaran
at a distance of 114", p. 35 deg.. There is an almost inexplicable charm
about these faint attendants of bright stars, which is quite different
from the interest attaching to a close and nearly equal pair. The
impression of physical relationship is never lacking though it may be
deceptive, and this awakens a lively appreciation of the vast
differences of magnitude that exist among the different suns of space.

The actual size and might of this great red sun form an attractive
subject for contemplation. As it appears to our eyes Aldebaran gives one
twenty-five-thousand-millionth as much light as the sun, but if we were
placed midway between them the star would outshine the sun in the ratio
of not less than 160 to 1. And yet, gigantic as it is, Aldebaran is
possibly a pygmy in comparison with Arcturus, whose possible dimensions
were discussed in the chapter relating to Booetes. Although Aldebaran is
known to possess several of the metallic elements that exist in the sun,
its spectrum differs widely from the solar spectrum in some respect