Capella in the birth chart: the bright fixed star of Auriga

Star data

sefstars catalogue, Swiss Ephemeris 2.10.03.

Capella is the bright star of Auriga, the Charioteer, and in the tropical zodiac it stands near the end of Gemini. The name is Latin and means "little she-goat". Ptolemy describes the bright stars of Auriga as a mix of Mars and Mercury.

In the sky

Auriga is not a zodiac constellation. It sits well north of the band the Sun, Moon and planets travel through, and Capella with it, more than twenty degrees north of the ecliptic. Regulus and Aldebaran, by contrast, lie close to the ecliptic, and the Moon passes in front of them.

That makes Capella's zodiac degree a projection rather than a place the planets ever pass. A planet "conjunct Capella" in longitude shares the star's degree, but in the sky the two are far apart. For stars like this some astrologers turn to parans, while others use longitude conjunctions as they do for any star.

Capella is the sixth-brightest star of the night sky. At around 50° north it never sets: it is circumpolar everywhere north of about 44°, which takes in all of Ukraine. On winter evenings it stands almost overhead, close to the zenith at its highest, and in summer it hangs low over the northern horizon. The easiest way to find it in winter is to look high above Orion for a bright yellowish star with a few fainter stars close beside it, the Kids.

What kind of star it is

What looks like one star to the eye is a multiple system. The light comes mostly from two yellow giants, each about two and a half times the mass of the Sun, one about twelve and the other about nine times its radius. They circle each other every 104 days, too close together to split with an ordinary telescope, and their orbit is turned so that they never eclipse each other. Both have already used up the hydrogen in their cores and swelled into giants, but they stand at different points on that path. The cooler one has a surface temperature of about 4,900 K, the hotter about 5,700 K, close to the Sun's, so Capella's yellow is a blend of two slightly different shades. Much further out, a pair of faint red dwarfs belongs to the same system. The whole group is about 42 light-years away.

Astrology treats the system as a single point.

The name and the goat

The name is the Latin diminutive of capra, "she-goat", and according to Allen's Star Names and Their Meanings (1899) it has been in use since Manilius, Ovid and Pliny. Ptolemy calls the star simply Aix, "the Goat", and Allen gives the Arabic name al-Ayyuq the same meaning. The star was known much earlier in Mesopotamia: in the Babylonian astronomical compendium MUL.APIN it forms, with the eastern half of Auriga, the figure GAM, Gamlu, "the Crook", a shepherd's staff with a hooked end. Allen also notes that Ptolemy described Capella's colour as reddish, although to the eye it looks yellow. The International Astronomical Union confirmed Capella as the official name in 2016.

The goat in question is Amalthea, who nursed the infant Zeus. Aratus in the Phaenomena calls her "the holy Goat that, as legend tells, gave the breast to Zeus". Hyginus's Astronomica explains the picture: the Goat stands on the Charioteer, and the Kids are in his left hand. Ovid's Fasti adds that Zeus made stars of both the nurse and her horn, the horn of plenty. Capella itself had a weather reputation too: Aratus linked it with storms, and Pliny and Manilius after him called it a rain star. The Kids had a harsher one: Ovid calls them rainy, and their October rising, as Allen records, marked the close of the sailing season.

Nature by tradition

In the first book of the Tetrabiblos Ptolemy says the bright stars of Auriga are like Mars and Mercury. The overview explains how to read such comparisons.

Mercury stands for the mind, speech and learning; Mars for drive and quick decisions. Tradition reads the mixture as an active, restless intelligence that is not content with thinking and wants to act. Mars gives Mercury an edge and a sense of urgency, and Mercury gives Mars words and a plan.

Ptolemy uses the same pair for the shoulders of Orion, which is why Betelgeuse shares Capella's nature. It stands a few degrees further on, at the very end of Gemini. A planet in this stretch is checked against both stars, and the tight orb decides which one it touches.

Conjunctions with planets and angles

Capella is read through conjunction with planets and angles, within an orb of about 1°. Two examples show how the tradition reads a contact.

• Mercury on Capella. The star adds the Mars side to a planet that already shares half of its nature. Tradition sees here a quick, combative mind: someone who thinks aloud, enjoys an argument and picks up new subjects fast.
• Capella on the MC. On the Midheaven, the angle of work and reputation, the star's themes move into public life. Tradition links the Mars and Mercury mix with work that runs on speech, analysis or negotiation, and with a reputation for a sharp mind.

Precession and sign

Through precession Capella, like every fixed star, moves through the zodiac by about 1.4° a century. At the end of Gemini it still has several degrees to go, so it will stay in the sign for several more centuries.

For charts from the last century the shift reaches a degree and a half or a little more, and with an orb of about 1° that is a different point. So Capella's position is taken for the year of birth, not for today.

In celebrity charts

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

• Olivia Rodrigo: Saturn, orb 0°14′

Find fixed stars in your chart