Beyond the five major aspects, other angles have been proposed over the centuries.
Minor aspects are secondary angles between two planets, read by some schools with a reduced margin.
On the major side, there are the conjunction at 0 degrees, the sextile at 60, the square at 90, the trine at 120, and the opposition at 180.
The minor aspects complete this list: semi-sextile (30), semi-square (45), quintile (72), sesquisquare (135), biquintile (144), and quincunx (150). They come from dividing the circle by twelve, by eight, and by five.
Because they are less pronounced, minor aspects call for very narrow orbs, on the order of one to three degrees. They therefore involve few planets at a time. The site shows only the five major aspects, so that charts stay readable; minor aspects therefore do not enter into the chart calculation.
According to tradition, the quincunx links signs sharing no element or modality, hence a reading of adjustment; the quintile and biquintile are associated with talent and creativity. These readings are unevenly accepted and remain conventions. To spot them in your own chart, a reliable birth time is best, because these fine aspects move quickly and can disappear with a few minutes’ difference.
Ptolemy retains only the five major aspects in the Tetrabiblos, in Book I. Classical astrology sticks with them for a long time.
Johannes Kepler, in Harmonices Mundi in 1619, in Book IV, introduces new aspects based on musical harmonies, including the quintile, the biquintile, and the sesquisquare. The harmonic astrology of the 20th century pushed this logic further.
Many astrologers ignore minor aspects, out of caution about their number: adding more makes almost any chart full of aspects.
Others use them with tight orbs, even an orb of one degree. Harmonic astrologers place them at the heart of their method. The debate concerns less their existence than their real weight.
Schools do not all agree: the site sets out the positions without deciding for you, and states the setting it uses by default.
The authors and texts that establish or discuss this concept, with the passage when it is known.
The five major aspects only.
Adds new aspects, including the quintile (72°), the biquintile (144°), and the sesquisquare (135°).
The diagram’s figures are calculated by the site’s engine (Astronomy Engine) or taken from the recorded facts, never copied by hand.
| Aspect | Angle | Glyph | Origin |
|---|---|---|---|
| Semi-sextile | 30° | Modern (17th century) | |
| Semi-square | 45° | Kepler, 1619 | |
| Quintile | 72° | Kepler, 1619 | |
| Sesquiquadrate | 135° | Kepler, 1619 | |
| Biquintile | 144° | Kepler, 1619 | |
| Quincunx | 150° | Modern (17th century) |
The semi-sextile (30°), the semi-square (45°), the quintile (72°), the sesquisquare (135°), the biquintile (144°), and the quincunx (150°). Some authors add others, rarer ones. All rest on a division of the circle.
It is a question of method, with no common answer. Some astrologers skip them to keep a chart readable, others use them with orbs of one to three degrees. The major aspects form in any case the shared base.
For clarity. The five major aspects are the oldest and the most agreed upon, and they are enough to describe the main relationships in a chart. Adding the minor ones would multiply the lines without guaranteeing a more reliable reading.