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Half-hours with the Telescope - Being a Popular Guide to the Use of the Telescope as a - Means of Amusement and Instruction. by Richard Anthony Proctor
page 64 of 115 (55%)
since the distance between the components of [xi] has greatly diminished
of late. Both the components of [pi] are white, and their magnitudes are
3-1/2 and 6.

We shall next turn to an exceedingly beautiful and delicate object, the
double star [epsilon] Bootis, known also as Mirac and, on account of its
extreme beauty, called Pulcherrima by Admiral Smyth. The components of
this beautiful double are of the third and seventh magnitude, the
primary orange, the secondary sea-green. The distance separating the
components is about 3 seconds, perhaps more; it appears to have been
slowly increasing during the past ten or twelve years. Smyth assigns to
this system a period of revolution of 980 years, but there can be little
doubt that the true period is largely in excess of this estimate.
Observers in southern latitudes consider that the colours of the
components are yellow and blue, not orange and green as most of our
northern observers have estimated them.

A little beyond the lower left-hand corner of the map is the star
[delta] Serpentis, in the position shown in the Frontispiece, Map 3.
This is the star which at the hour and season depicted in Map 2 formed
the uppermost of a vertical row of stars, which has now assumed an
almost horizontal position. The components of [delta] Serpentis are
about 3-1/2 seconds apart, their magnitudes 3 and 5, both white.

The stars [theta]^{1} and [theta]^{2} Serpentis form a wide double, the
distance between the components being 21-1/2 seconds. They are nearly
equal in magnitude, the primary being 4-1/2, the secondary 5. Both are
yellow, the primary being of a paler yellow colour than the smaller
star. But the observer may not know where to look for [theta] Serpentis,
since it falls in a part of the constellation quite separated from that
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