♌ ♍ ♎ ♏ ♐ ♑ ♒ ♓
Cyclical · 12 signs
Zodiac
Twelve signs mapping the ecliptic into a repeating calendar of character. A system whose referents (the constellations) have drifted, but whose symbols persist — meaning outliving its astronomy.
- Grammar
- Twelve signs of exactly 30° each, partitioning the ecliptic. Every sign is one cell of a four-by-three grid — four elements crossed with three modalities — which is why there are twelve and cannot be eleven or thirteen. The grid is the grammar.
- Governance
- No authority over the signs. The constellations, however, were given fixed boundaries by the IAU in 1930 — an act of astronomical housekeeping that formally severed the signs from the stars they were named for.
- Members
- ♈ ♉ ♊ ♋ ♌ ♍ ♎ ♏ ♐ ♑ ♒ ♓ U+2648–U+2653
§Its members
The complete set of twelve — one cell of a four-by-three grid each.
Sources · 2
- documented Ptolemy, Tetrabiblos, 2nd c. — the sign system in its enduring form.
- documented Eugène Delporte, Délimitation scientifique des constellations, IAU, 1930 — the boundaries that made the drift official.