What is Conjunction in Western astrology?

Definition

Conjunction is a Western astrological aspect in which two placements share the same zodiacal longitude, an exact angle of 0 degrees between them.

In plain words

A conjunction is a Western astrological aspect in which two placements share the same zodiacal longitude, an exact angle of 0 degrees. Ptolemy's Tetrabiblos, in Thayer's Loeb-based edition, treats a bodily conjunction as one way a relation between bodies can arise. In astronomy, the word means something related but distinct: two objects appear close together in the sky, sharing either right ascension or ecliptic longitude.

Also asked as

• What angle is a conjunction?
• What orb is usually used for a conjunction?
• Is a conjunction harmonious or challenging?
• How is a conjunction shown on a chart?

History

The conjunction has long been treated in astrological writing as a special kind of contact between bodies. In Ptolemy's Tetrabiblos, in Thayer's Loeb-based edition, a relation between bodies counts as an application or separation whether it arises by bodily conjunction or through one of the traditional aspects, when the interval between them is not great. Deborah Houlding, on the SkyScript aspects pages, reports that many traditional texts say the conjunction should not be called an aspect, because conjoining planets join in physical reality rather than meeting by sight. She explains that the term corporeal is commonly attached to it to stress an actual bodily union rather than a blending of rays.¹⁵

Quick timeline

1. Early record — The conjunction has long been treated in astrological writing as a special kind of contact between bodies. In Ptolemy's Tetrabiblos, in Thayer's Loeb-based edition, a relation between bodies counts as an application or separation whether it arises by bodily conjunction or through one of the traditional aspects, when the interval between them is not great. Deborah Houlding, on the SkyScript aspects pages, reports that many traditional texts say the conjunction should not be called an aspect, because conjoining planets join in physical reality rather than meeting by sight. She explains that the term corporeal is commonly attached to it to stress an actual bodily union rather than a blending of rays.¹⁵
2. Classical framework — In Thayer's Loeb-based edition of Ptolemy's Tetrabiblos, a relation between bodies counts as an application or separation whether it arises by bodily conjunction or through one of the traditional aspects, when the interval between them is not great. The same edition describes the conjunction as the 0-degree relationship between two zodiacal longitudes. Deborah Houlding, on the SkyScript aspects pages, reports that many traditional texts say the conjunction should not be called an aspect, since conjoining planets join in physical reality rather than meeting by sight.¹⁵
3. Later transmission — Wikipedia's astronomy article on conjunctions notes that the conjunction symbol, Unicode U+260C, is not used in modern astronomy, although it continues to be used in astrology. The Astrological aspect article explains that a conjunction may be beneficial or detrimental depending on the planets involved. It cites the Sun, Venus and Jupiter as highly favourable combinations. Readers can treat this as an interpretive frame rather than a fixed rule. Studying which bodies are involved is a constructive practice, because the same 0-degree contact can be read in different ways depending on the placements.³⁴

What classical and modern sources say

Classical view

In Thayer's Loeb-based edition of Ptolemy's Tetrabiblos, a relation between bodies counts as an application or separation whether it arises by bodily conjunction or through one of the traditional aspects, when the interval between them is not great. The same edition describes the conjunction as the 0-degree relationship between two zodiacal longitudes. Deborah Houlding, on the SkyScript aspects pages, reports that many traditional texts say the conjunction should not be called an aspect, since conjoining planets join in physical reality rather than meeting by sight.¹⁵

Modern view

Wikipedia's astronomy article on conjunctions notes that the conjunction symbol, Unicode U+260C, is not used in modern astronomy, although it continues to be used in astrology. The Astrological aspect article explains that a conjunction may be beneficial or detrimental depending on the planets involved. It cites the Sun, Venus and Jupiter as highly favourable combinations. Readers can treat this as an interpretive frame rather than a fixed rule. Studying which bodies are involved is a constructive practice, because the same 0-degree contact can be read in different ways depending on the placements.³⁴

Angle, orb and interpretation

Exact angle

Conjunction is the 0-degree relationship between two zodiacal longitudes, as Ptolemy's Tetrabiblos describes it in Thayer's Loeb-based edition. The angle measures how close two placements sit along the zodiac.¹

Orb

A common allowance is 8 degrees, and wider allowances are often used for the luminaries. Orb conventions vary between practitioners and are not astronomical constants. Treating the orb as a convention keeps the reading transparent.¹

Interpretive frame

A conjunction concentrates two placements in the same part of the zodiac. Constructive use depends on the bodies involved, so the aspect becomes a practice of attention rather than a verdict.¹

Geometry

Two rays separated by 0 degrees show the geometric definition. This keeps the angle distinct from interpretation, so the angle is not treated as a measured force.¹

The astronomy

In astronomy, a conjunction occurs when two astronomical objects or spacecraft appear to be close to each other in the sky, usually as observed from Earth. They share either the same right ascension or the same ecliptic longitude. Wikipedia's astronomy article on conjunctions states that conjunction in right ascension and conjunction in ecliptic longitude do not normally occur at the same moment, though they usually happen nearly simultaneously. This timing difference is a useful point for beginners to notice when comparing astronomical and astrological usage.³

Where astrologers differ

Astronomical and astrological usage share a word but differ in method and purpose. Wikipedia's astronomy article on conjunctions notes that right-ascension and ecliptic-longitude conjunctions usually occur nearly but not exactly together. The Astrological aspect article notes that astrologers use differing orbs, and that almost all astrologers allow a larger orb for a conjunction than for other aspects. Deborah Houlding, on the SkyScript aspects pages, reports that Ibn Ezra, writing in the 12th century, said the ancients would not treat a conjunction as valid unless both planets were also in the same sign, though Ezra himself disagreed with this rule.

Then and now

Then

In Thayer's Loeb-based edition of Ptolemy's Tetrabiblos, a relation between bodies counts as an application or separation whether it arises by bodily conjunction or through one of the traditional aspects, when the interval between them is not great. The same edition describes the conjunction as the 0-degree relationship between two zodiacal longitudes. Deborah Houlding, on the SkyScript aspects pages, reports that many traditional texts say the conjunction should not be called an aspect, since conjoining planets join in physical reality rather than meeting by sight.¹⁵

Now

Wikipedia's astronomy article on conjunctions notes that the conjunction symbol, Unicode U+260C, is not used in modern astronomy, although it continues to be used in astrology. The Astrological aspect article explains that a conjunction may be beneficial or detrimental depending on the planets involved. It cites the Sun, Venus and Jupiter as highly favourable combinations. Readers can treat this as an interpretive frame rather than a fixed rule. Studying which bodies are involved is a constructive practice, because the same 0-degree contact can be read in different ways depending on the placements.³⁴

Worked out from the evidence

Reasoned from the cited facts, not stated outright by any one source.

Because Ptolemy's Tetrabiblos treats bodily conjunction as one way a relation between bodies arises, and Houlding reports that traditional texts call the conjunction a physical union rather than an aspect seen by sight, the conjunction reads as a contact of bodies rather than a purely angular link.

Because astronomy uses the same word for objects sharing right ascension or ecliptic longitude, while astrologers allow a wider orb for a conjunction than for other aspects, the astronomical and astrological senses agree on the shared position but differ on how closeness is measured.

Not yet confirmed

• Which orb size traditional astrologers in Ptolemy's period would have applied to a conjunction is not stated in the Tetrabiblos excerpt used here.
• How the 12th-century rule attributed to Ibn Ezra about sharing a sign was applied in practice is not settled by the SkyScript aspects pages.

Follow the parts of Conjunction

Continue through Opposition, Sextile.

Questions people also ask

What angle is a conjunction?

In Ptolemy's Tetrabiblos, in Thayer's Loeb-based edition, a conjunction is the 0-degree relationship between two zodiacal longitudes. Two placements sharing that exact longitude form the conjunction.¹

What orb is usually used for a conjunction?

The Astrological aspect article notes that astrologers use differing orbs. Almost all astrologers allow a larger orb for a conjunction than for other aspects, so the allowance is a convention rather than a fixed rule.⁴

Is a conjunction harmonious or challenging?

The Astrological aspect article explains that a conjunction may be beneficial or detrimental depending on the planets involved. Highly favourable conjunctions may involve the Sun, Venus, and Jupiter.⁴

Method and review

Every statement about Conjunction was checked against the wording of its 5 sources (Ptolemy (LacusCurtius), Encyclopaedia Britannica, Wikipedia and Skyscript), and its positions and boundaries were calculated with Astronomy Engine. How the Machine works.