Fixed star

Meaning

The ancients split the night sky in two. The planets were the wanderers, from the Greek planētēs. Everything else kept its place in the constellations, night after night, and was called fixed.

Astrology reads a fixed star through the zodiac. Each star is projected onto the ecliptic, the Sun’s yearly path, and given a degree like a planet. When a planet or an angle sits on that degree, tradition reads it as taking on some of the star’s character. A second voice joins its own.

The stars are not quite fixed. A slow wobble of the Earth’s axis, called precession, carries them forward through the tropical zodiac. They move about 50 seconds of arc a year, one degree in about 72 years. Regulus stood at 29°50′ Leo in 2000 and crossed into Virgo around 2011–12.

Since Ptolemy, each star’s nature has been described by comparison with the planets. Aldebaran is like Mars, Spica like Venus with a little Mars. These comparisons are a shorthand for a temperament, not a verdict.

In practice

• The orb is small. A star is a point of light, and most astrologers allow about a degree, sometimes less, for a conjunction.
• Conjunctions come first. Few astrologers use other aspects to stars. A star on the Sun, the Moon, the Ascendant or the Midheaven is read most strongly.
• Latitude counts for some. Algol lies about 22° north of the ecliptic and Fomalhaut about 21° south. A planet on their degree is far from them in the sky, so some astrologers weigh such contacts less.
• A star colours; it does not decide. Its contact is read within the whole chart. The planet’s sign, house and aspects remain the main story.
• Parans. Bernadette Brady also reads stars by their parans. A paran is a moment of the birth day when a star and a planet stand on the horizon or the meridian together.

Across traditions

• Indian astrology divides the zodiac into 27 lunar mansions, the nakshatras, each named after its stars. Aldebaran marks Rohini, Regulus Magha, Spica Chitra and Antares Jyeshtha. Its sidereal zodiac moves with the stars, so a star keeps its degree there.
• Chinese astronomy has its own 28 lunar lodges and star groups. Antares, for example, is the second star of the Heart lodge, 心宿二 Xīnxiù’èr.

Origin and history

Babylonian astronomers followed the Moon and the planets against a set of bright reference stars near the ecliptic. In the 2nd century BC, Hipparchus compared his measures of Spica with older ones. The stars had shifted: he had found precession. Ptolemy reports it in the Almagest, whose catalogue lists 1,022 stars in 48 constellations, each with its position and brightness. In the Tetrabiblos he gives the brightest stars their planetary natures.

Medieval and Renaissance magic singled out fifteen Behenian stars, each paired with a stone and a plant. Agrippa lists them in his De occulta philosophia. Algol, Aldebaran, Regulus, Spica and Antares are among them. Vivian Robson gathered the astrological tradition in 1923, and Bernadette Brady reworked it in 1998 through myth and parans.

How Ulune calculates it

Ulune charts six stars: Aldebaran, Regulus, Antares, Fomalhaut, Spica and Algol. Their positions come from the Swiss Ephemeris star catalogue, sefstars.txt. Each is the star’s apparent position at the chart’s moment, in the same frame as the planets. Precession, nutation, aberration and the star’s own motion are applied.

Ulune compares longitudes only: a body within 1° of a star’s longitude is on it, whatever its ecliptic latitude. The Stars part of the chart table lists, for each star, every body, point and angle on it except the lots, closest first. Without a birth time, a contact that may not hold all day is marked ~.

On the wheel, the stars are an overlay, turned on in the Bodies panel. A star’s mark names the closest of the Sun, Moon, Mercury, Venus, Mars or the four angles within 1° of it. In a composite chart, each star stands at the midpoint of its positions in the two charts.

Correspondences