Analyze your birth chart with 115 fixed stars. Ecliptic conjunction, declination parallel and paranatellonta (paran) calculations on a single page.
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Fixed stars are distant suns that appear nearly motionless relative to the zodiac belt, unlike planets. While planets move through signs over weeks or years, fixed stars shift only about 1 degree every 72 years due to precession. When a fixed star makes a close conjunction with a planet or angle in the birth chart, it adds a powerful additional layer of meaning to that placement.
The tradition of interpreting fixed stars dates back to Babylonian astrology and was systematized by Ptolemy. Ptolemy assigned each star a "planetary nature." For example, Regulus has a Mars-Jupiter nature: combining ambition with authority. This system still forms the foundation of fixed star interpretation today. Remember that the nature of fixed stars is for classification purposes only.
Start with the Conjunctions tab. These show fixed stars close to your natal planets via ecliptic longitude. Stars are sorted by class: Royal Stars carry the strongest influence, followed by Behenian stars, then traditional stars. A tighter orb means a stronger contact: a 0.2-degree conjunction is far more prominent than a 1.5-degree one.
Declination parallels occur when a planet and star share the same celestial declination (distance north or south of the celestial equator). Parallels act like conjunctions and are especially important for stars far from the ecliptic. For example, Sirius has a declination of -16.7 degrees and an ecliptic latitude of -39.6 degrees. Therefore Sirius's projection in ecliptic longitude (14 degrees Cancer) does not reflect its true celestial position, but a planet near -16.7 degrees declination is physically in the same celestial band as Sirius.
Parans (paranatellonta), are calculated for your specific birth latitude and require an exact birth time. A paran occurs when a star and planet are simultaneously at one of four important points (rising, setting, culmination, anti-culmination). Brady's paran method is considered the most accurate way to assess fixed star influence because it uses the star's actual position in the sky rather than its projected ecliptic longitude position.
The four Royal Stars (Aldebaran, Regulus, Antares, Fomalhaut) are among the brightest stars near the ecliptic and mark the four quarters of the sky. In Persian astrology, they were considered the four Watchers (Guardians) of the heavens. They carry the strongest fixed star influence in a birth chart. Each holds a great promise, but that promise comes with a test: Aldebaran the test of integrity, Regulus avoiding revenge, Antares resisting excess, Fomalhaut not corrupting ideals.
Used in medieval talismanic tradition, the 15 Behenian stars (from the Arabic bahman meaning "root") are each associated with a specific gemstone, plant and symbol. Detailed in Agrippa's Occult Philosophy, these stars are Algol, Alcyone, Sirius, Procyon, Capella, Arcturus, Spica, Alphecca, Vega, Altair, Deneb Algedi, Pollux, Denebola, Alnilam and Regulus (Regulus belongs to both the Royal and Behenian groups).
Orb varies by star magnitude. The system used in this calculator: 1st magnitude and brighter stars (like Sirius, Vega, Arcturus) use up to 2 degrees orb. 2nd magnitude stars use 1.5 degrees, 3rd magnitude uses 1 degree, and fainter stars use 0.5 degrees orb. For stars far from the ecliptic, the conjunction is based on projection so the actual effect may be weaker. In such cases, declination parallels and parans are more reliable indicators.
About fixed stars and their natal interpretation
Fixed stars are the luminous points of the night sky beyond the Sun's planetary system whose mutual positions appear constant over a human lifetime, in contrast to the wandering planets (Greek planetes, "wanderers") which move noticeably from night to night. In traditional astrology a select group of bright stars - around 115 in the Robson and Brady canon - is considered to imprint specific qualities on the chart when conjoined with a natal planet, angle or lot. Their effect was first systematized by Ptolemy in the Tetrabiblos (Book I) and by Hellenistic and medieval Arabic authors who assigned each star a "planetary nature" such as Mars-Saturn or Venus-Jupiter.
Two coordinate systems are used in fixed-star work: ecliptic longitude (with a small latitude offset from the ecliptic plane) is used for conjunctions with natal planets in the chart wheel, while declination - the star's angular distance north or south of the celestial equator - is used for parallels of declination, where a star and a planet occupy the same declination and so behave as if conjoined. The two methods often disagree; classical authors privileged ecliptic conjunctions within tight orbs (typically one degree), while parallels became more important in twentieth-century cosmobiology and Bernadette Brady's work on fixed stars.
Each prominent fixed star has been assigned by Ptolemy and the later tradition the temperament of one or two planets that best describe its observed action. Algol (Caput Algol, the head of Medusa) is "of the nature of Saturn and Jupiter" in Ptolemy and "of Saturn and Mars" in Vivian Robson, traditionally one of the most violent stars in the sky. Sirius is described as "of the nature of Jupiter and Mars," promising honor and renown when well placed. Regulus is purely Mars-Jupiter, a star of royalty; Spica is Venus-Mars, and Aldebaran is the Bull's Eye, of Mars nature. These nature attributions guide interpretation when a star contacts a natal point.
Apparent magnitude measures how bright a star appears from Earth, on a logarithmic scale where lower numbers are brighter (Sirius at -1.46, Spica at +1.04, Polaris at +1.98, the dimmest stars visible to the naked eye at +6). Most traditional astrologers restrict fixed-star interpretation to stars of first magnitude (brighter than +1.5) and the most important second-magnitude stars, on the principle that visible brightness reflects astrological significance. Brady, Robson and Ebertin together identify roughly 115 stars of interpretive interest, with the brightest dozen carrying the largest individual weight when contacting a planet, angle or lot.
Paranatellonta is the Greek term for "rising together," and in fixed-star astrology it denotes the moments when a fixed star is angular (rising, culminating, setting or anti-culminating) at the same time as a natal planet. Such parans bind the star and the planet for life, regardless of whether they share an ecliptic conjunction. The technique reaches back to Egyptian decanal astronomy and is preserved in the Hermetic Liber Hermetis and the Salmeschoiniaka; in modern practice, Bernadette Brady has revived paran analysis as a primary tool for fixed-star interpretation, complementing the older ecliptic conjunction method.