Alcyone in the birth chart: the brightest star of the Pleiades

Star data

sefstars catalogue, Swiss Ephemeris 2.10.03.

Alcyone is the brightest star of the Pleiades, and when astrologers want a single point for the whole cluster, they take this one. In the tropical zodiac it now stands at the very start of Gemini. It crossed over from Taurus around 2000, so older books and tables still place it at the end of Taurus.

In the sky

The Pleiades belong to the constellation Taurus, and Alcyone sits among them, yet in the zodiac it is already in Gemini. A star keeps its constellation for good, while its sign changes every two thousand years or so: precession has pulled constellations and signs apart.

The cluster is a group of stars close together, and older astrology treated it as a group. Ptolemy describes the Pleiades as a whole, not star by star. Alcyone stands for them simply because it is the brightest, which gives astrologers one position to measure from instead of a small patch of sky.

The cluster lies about 444 light-years away. That figure comes from radio telescope measurements published in 2014, which settled a long argument: the Hipparcos satellite had placed the Pleiades about ten percent closer.

From mid-northern latitudes the Pleiades are an autumn and winter sight. At around 50° north they climb more than 60° above the southern horizon, reach their highest point at midnight in mid-November and stay in the evening sky until early spring. They are easy to find: a small, tight dipper of stars above and to the right of Aldebaran, often mistaken for the Little Dipper. Most people count six stars with the naked eye, and Aratus already noticed this in the Phaenomena: the songs speak of seven sisters, but only six can be seen.

The name

Alcyone is one of the Pleiades, the daughters of Atlas and Pleione in Greek myth. In Hyginus's Astronomica she is the mother of Hyrieus by Poseidon. The Arabic name of the cluster is al-Thurayya, which Allen's Star Names and Their Meanings (1899) renders as "the many little ones". In Ukrainian folk tradition the cluster is Stozhary, also called the Seven Sisters or the Brood Hen, with Volosozhary as an older form. The International Astronomical Union confirmed Alcyone as the star's official name in 2016.

The cluster also lends its story to a neighbour: Aldebaran gets its Arabic name, "the follower", from the way it comes after the Pleiades across the sky. In the zodiac the order holds. Alcyone sits at the very start of Gemini, Aldebaran further on, in the first third of the sign.

Myth and the farming year

The best-known story about the Pleiades links them to Orion. Hyginus tells that Orion pursued Pleione and her daughters for seven years, until Zeus took pity on the sisters and set them among the stars, and that Orion still seems to follow them as they move west across the sky. Hesiod's Works and Days uses the cluster as a calendar: when the Pleiades are rising, in May, begin the harvest, and when they are setting, in November, begin the ploughing. For a Greek farmer this small patch of sky marked the turning points of the year.

In the nineteenth century the astronomer Johann Heinrich Mädler placed the centre of the universe in Alcyone. The idea did not survive, and Allen records it as already refuted by 1899.

Nature by tradition

In the first book of the Tetrabiblos Ptolemy gives the Pleiades the nature of the Moon and Mars. That is the reading in Ashmand's translation (1822) and in Robson's handbook (1923); Robbins's Loeb translation (1940) has Jupiter instead of Mars, and this page follows the first reading. Ptolemy describes a star through the planets whose effects it resembles, and the overview explains how to read such comparisons.

The two planets in this pair pull in different directions. The Moon stands for feelings, the body and everyday needs; Mars for drive, heat and the readiness to act. Put together, tradition reads them as sensitivity with an edge: reactions come fast, and feeling turns easily into action. The Moon makes Mars more personal, and Mars makes the Moon less passive.

Conjunctions with planets and angles

Alcyone is read mainly by conjunction, with a tight orb of about 1°. Two examples show the logic.

• Moon on Alcyone. Here a lunar star meets the Moon itself, so the Moon's themes grow stronger, and Mars adds speed to them. Tradition reads this as a strong emotional response that shows on the surface: moods shift quickly, and other people notice.
• Alcyone on the Ascendant. On the Ascendant a star shapes the manner, the way a person meets the world. The Mars side shows as directness and a readiness to answer back; the Moon side as sensitivity to other people's moods. The two sit together in one character without much friction: quick to react and quick to feel.

Precession and the sign change

For Alcyone precession has a visible result: around 2000 the star moved from the last degree of Taurus into Gemini. It shifts by about 1.4° a century, so its position is checked for the year of birth rather than for today.

For someone born in the middle of the last century the difference is about a degree, as wide as the whole orb. A planet at the end of Taurus in a chart from the 1950s may be on Alcyone, while the same degree today no longer is.

Neighbours in Gemini

The start of Gemini opens a busy stretch of the zodiac. After Alcyone come Aldebaran and Rigel, and nearer the end of the sign stand Capella and Betelgeuse. In a chart with several planets in Gemini, each one is checked against this list with a tight orb, so that a star is not claimed for a planet several degrees away.

In celebrity charts

Conjunctions within 1° to the planets from the Sun to Saturn and to the chart angles.

• Emmanuel Macron: IC, orb 0°19′
• Barack Obama: IC, orb 0°31′

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