Page:Star Lore Of All Ages, 1911.pdf/515

Rh of Prosperity," "the Propitious One of Seed," "the One called Ear of Corn," and "the Corn Bearer."

Spica is especially interesting as furnishing Hipparchus the data which enabled him to discover the Precession of the Equinoxes. According to Lockyer, a temple at Thebes was oriented to Spica as early as 3200 Other temples oriented to this star are found at Olympia, Athens, and Ephesus. At Rhammus there are two temples almost touching each other, both following the shifting places of Spica. Many other temples were dedicated to Spica, and it seems to have been associated with the Min-worship of the Egyptians.

Spica is a spectroscopic binary, one of those stars which the spectroscope has shown to be attended by an invisible companion of enormous mass. Spica's dark companion revolves about it in a close orbit, making a complete revolution in the remarkably short period of four days. Spica is at such an enormous distance from us, that no reliable parallax has been obtained. Owing to its proximity to the ecliptic Spica is much used in navigation. It is a star of the Sirian type, and is said to be approaching our system at the rate of 9.2 miles a second. The star rises a very little south of the exact eastern point on the horizon, and culminates at 9. May 27th.

The star γ Virginis, known to the Latins as "Porrima," is an interesting star. Allen tells us that it is especially mentioned by Kazwini as being the "Angle" or "Corner of the Barker."

The Chinese knew it as "the High Minister of State."

It is a beautiful double star, and a fine sight in a small telescope, the two stars being about equal in brilliance, 3 and 3.2 magnitudes. In 1836 they showed as a single star, so close were they together, and consequently were indivisible even in the largest telescopes. Now they are 6″ apart, with a period of revolution estimated at about 190 years. Almost a complete revolution has been observed. The star culminates at 9, May 17th.