Spica

Meaning

Spica is the brightest star of Virgo. Its Latin name means “ear of grain”, the ear of wheat the Virgin holds in her hand. The Greeks called it Stachys, with the same meaning. The figure has been read as a goddess of the harvest, and the star as the promise of a crop.

It shines at about magnitude 1 and lies some 250 light-years away. It is in fact two hot blue stars, so close that they circle each other in about four days. It lies about 2° south of the ecliptic, near enough for the Moon to pass in front of it in some years. Its degree was 23°50′ Libra in 2000, and it moves forward about a degree in 72 years.

Ptolemy likens Spica to Venus and, to a lesser degree, Mars. Tradition counts it among the most fortunate stars of the sky. It is read as a gift: talent, skill, grace and the knack of bringing things to fruit. Mars’s share adds the energy to work that gift. Its difficult side is mild: a talent taken for granted.

In practice

• On the Sun or the Ascendant, Spica is read as a natural gift that others notice, and an ease that opens doors.
• On the Midheaven, it is read as recognition for skill or craft, often in work that refines or brings things to harvest.
• On Venus, the two voices agree: tradition reads charm, artistic feeling and a generous spirit.
• On the Moon or Mercury, it is read as a quick, receptive mind and a gift for learning.
• By sign, it stands in late Libra in the tropical zodiac, though it belongs to the constellation Virgo.

Across traditions

• Indian astrology places it in the nakshatra Chitra, “the bright”. The Lahiri ayanamsa, the sidereal zodiac most used in India, is set so that Spica stands at or very near 0° Libra.
• Chinese astronomy calls it 角宿一 Jiǎoxiùyī, the first star of the Horn lodge, itself the first of the 28 lodges.
• Greek myth links Virgo with Demeter, the harvest goddess, or with her daughter Persephone, and the ear of wheat is their sign.

Origin and history

Spica holds a special place in the history of astronomy. In the 2nd century BC, Hipparchus measured its distance from the autumn equinox. He compared it with a measure Timocharis had taken over a century earlier. The gap had shrunk by about two degrees: the stars were drifting against the equinoxes. Ptolemy tells the story in the Almagest, and that drift is precession.

In the Tetrabiblos, Ptolemy gives Spica the nature of Venus with some Mars. Medieval magic counted it among the fifteen Behenian stars, and Agrippa lists it in his De occulta philosophia. Vivian Robson, in 1923, gathered the readings that make it one of the most fortunate stars.

How Ulune calculates it

Ulune places Spica from the Swiss Ephemeris star catalogue, sefstars.txt, where it is Alpha Virginis. Its position is the apparent one at the chart’s moment, with precession, nutation, aberration and the star’s own motion applied.

A body within 1° of Spica’s longitude counts as on it; latitude is not compared. The Stars part of the chart table lists every body, point and angle on the star except the lots, closest first. Without a birth time, a contact that may not hold all day is marked ~. On the wheel, Spica is an overlay turned on in the Bodies panel. Its mark names the closest of the Sun, Moon, Mercury, Venus, Mars or the four angles within 1°.

Correspondences