Stellium: three or more planets in one sign

AstralPro uses a strict definition: a stellium is at least three planets in the same sign. Your report's glossary sums it up this way: “A cluster of at least three planets in the same sign; it strongly concentrates the chart's energy.” Only the ten planets count, from the Sun to Pluto. The North Node, Lilith, Chiron, the asteroids and the angles do not complete a group of two planets.

The criterion is the sign, not the house. Three planets gathered in one house but spread over two signs do not form a stellium in the report's sense: it then speaks of a cluster in a house, or of a concentration in a sign, and never uses the word stellium for a group that does not meet the condition.

The word is fairly recent: formed on the Latin stella, star, it appears in English as early as 1819, in James Wilson's dictionary of astrology. 17th-century astrologers spoke of a satellitium, from the Latin satelles, an escort: planets gathered like a retinue around an important figure. Tradition kept this name for a remarkable occurrence, four or five planets packed into the same sign or the same house.

Definitions vary: some authors require four planets, others three; some also count groups gathered in the same house, others require the planets to be all conjunct with one another. Others still add the angles or the Nodes to the count. AstralPro keeps to the most legible criterion and the easiest to check on your positions table: three planets, one sign.

Chapter I, Natal Chart, opens with a section titled “Dominant configuration”. It names the most striking grouping in the chart and lists the planets concerned, keeping only those actually in the announced sign, never those that merely share the house. It then describes what this concentration produces in the way of thinking, acting and feeling, offers two complementary angles of reading if needed, then provides a counterpoint: a missing element, an isolated planet, a secondary concentration.

When the chart contains no stellium, the section exists all the same and describes another dominant feature, without using the word. The Book, for its part, devotes a chapter to the major figures of the chart, where the stellium is identified alongside T-squares, grand trines, grand crosses and yods; its count there also includes the Ascendant and the Midheaven.

The stellium is not only discussed, it enters the calculation of the dominants. In the weighted method AstralPro uses for the element and modality bars, each planet belonging to a stellium receives an extra point, on top of its own weight. A heavily occupied sign therefore pulls its element and its modality upward, beyond a simple count of planets.

That is why a stellium can often be recognized at a glance in the bars: one element or one modality clearly takes the lead over the others.

For Camille Morel, AstralPro's sample chart (fictional data), the stellium is clear-cut. Six of the ten planets are in Scorpio: Jupiter at 0°50', Venus at 6°30', Mercury at 6°37', the Sun at 21°55', Pluto at 25°17' and the Moon at 27°09'. Her Ascendant is also in Scorpio, at 15°59', but it does not count in the natal stellium.

This stellium crosses two houses: Jupiter, Venus and Mercury are in house 12, the Sun, Pluto and the Moon in house 1. It is a stellium of sign, not of house, and this distribution opens two angles of reading for the Dominant configuration: what is prepared under cover in house 12, what asserts itself in house 1. Mars, alone in Sagittarius, and Saturn, alone in Aquarius, provide the counterpoint.

The dominants bear its mark: Water reaches 76% and Fixed 82% in the bars of her report, and the five dominant planets, Pluto, the Sun, Mercury, Venus and the Moon, are all in Scorpio. Pluto, ruler of Scorpio and in domicile, is the dispositor of all the other planets in the group: this stellium has a center.

A stellium is not a series of conjunctions. Planets gathered in one sign can be nearly 30° apart from one another, with no aspect between them, while two planets straddling two signs can be conjunct without forming a stellium. The stellium describes a shared color, that of the sign; the conjunction describes a fusion of two functions, measured by its orb.

In Camille's chart, the two partly overlap. In Scorpio, the aspect grid records Mercury conjunction Venus (0°07'), Moon conjunction Pluto (1°52'), Sun conjunction Pluto (3°23'), Sun conjunction Moon (5°15'), Venus conjunction Jupiter (5°40') and Mercury conjunction Jupiter (5°47'). Jupiter, at 0°50', and the Moon, at 27°09', nevertheless belong to the same stellium without forming an aspect: more than 26° separate them.