The name Spica comes from Latin, meaning “ear of wheat”. It is the brightest star in the constellation Virgo, which rules the harvest season.
Like many bright stars, it is actually a binary star, with one much brighter than the other. They are actually in very close orbit, one-fourth as close as the Earth and the Sun, so close that they cause tidal distortion to each other. (It takes just four days for them to complete their circle.)
One of them is much larger and brighter than the other, pulsating outward and contracting, while the other is smaller. Both rotate very rapidly on their axes as well, so this may be a young star system. They don’t eclipse each other from our angle, but they do hide parts of each other, dimming each in turn.
Spica was interesting to ancient scientists, too. The ancient Greek astronomer Hipparchus discovered the precession of the equinoxes from observations of Spica. (This is the wobble in the Earth’s axis that changes the position of the stars relative to us over time, and will eventually oust Polaris from its position as the North Star.)
Virgins and Harvests
Virgo means “virgin”, and the Greeks said that the constellation represented the goddess Astraea, a Titan who lived among humans during the Golden Age, but fled to the sky when crime became rampant. She stayed in the sky as a reminder of a more innocent time.
Going from the celestial to the infernal, the Romans saw Persephone in the constellation, the young goddess that Hades kidnapped to be his bride. To the Egyptians, Virgo was Isis; she and her husband Osiris taught humans to sow and reap grain, and how to brew barley beer. (Spica was sometimes called her lute player.)
Hangovers and Suicide
The Egyptians might have brewed beer, but the Greeks liked wine, and another story about Virgo focuses on the grape harvest. The wine god Dionysus taught a mortal, Icarius, to make wine, which he unwisely shared with some shepherds. Experiencing the first hangover of their lives made them think Icarius had poisoned them, and they killed him and buried his body.
Icarius’s daughter went looking for her father, and she found his grave with the help of his faithful dog. She was brokenhearted, and hung herself from a tree. Dionysus was not amused by the poor reception his gift to humanity received, and he sent madness to the countryside, until all the young women of Athens had hanged themselves.
To propitiate the spirits of Icarius, Erigone and, yes, even the dog, they were placed among the stars as Boötes, Virgo, and Procyon. The Greeks also founded a festival in their honour, called Aiora, the Swing. The name came from the ritual of swinging small images from trees. (I suspect the myth may have come after the ritual.) There were also offerings of fruit, since it was a harvest festival.
Ovid, in his Metamorphoses, suggests Dionysus had a personal interest in Erigone, disguising himself as a bunch of grapes to seduce her. (He tells how Arachne included this episode in her tapestry of gods seducing maidens in various undignified ways. You might remember that this was unwise of her.)
The constellation did forecast the grape harvest, as Epsilon Virginis was called Protrygetor, Forerunner of the Vintage. (Bayley: 178) They must have been really looking out for it, as Spica is the only really bright star in the constellation.
China adopted the constellation Virgo, in the 17th century, but, earlier, Spica alone was the sign of the first lunar mansion, representing the beginning of the eastern portion of the sky; it was the first sign of the Green Dragon section of the sky, called his horn.
The Arabs called it Al Simak al A’zal, the Defenceless Simak. Unlike the other Simak, Arcturus, it had no other stars near it. The Hindus called it Citra, Pearl, the 12th lunar mansion. They assigned the artificer-god Tvashtar as its ruler. (Allen)
To the Luiseño of Southern California Spica was one of their sky-chiefs, Waonesh. The Zuñi of New Mexico and Arizona made Spica part of their enormous constellation Chief of the Night. This covered the entire sky, and Spica was his elbow, with Arcturus as his shoulder, and Antares on his forearm, while a cluster of stars in Sagittarius was his hand. (Miller)
Astrology and Spica
In astrology, Spica stands for success and prosperity, as fits the star of the harvest. Its gem is the emerald. (Pennick: 66) With Denebola, Regulus, and Arcturus it forms the Diamond of Virgo. It is at it hightest point in the sky (culmination) on April 8th.
Allen, Richard H. 1963: Star Names: Their Lore and Meaning, Dover Publications. (reprint)
Bayley, Michael 1997: Caer Sidhe vol. 1: The Celtic Night Sky, Capall Bann.
Eratosthenes, C. Julius Hyginus, trans. Condos, Theony 1997: Star Myths of the Greeks and Romans: A Sourcebook, Phanes Press.
McGrath, Sheena 2006: Sun, Moon and Stars, Capall Bann.
Miller, Dorcas S. 1997: Stars of the First People, Pruett Publishing Co., Boulder, CO.