Stellium

A grouping of three or more planets in the same zodiac sign or the same house, producing an unusually strong concentration of energy in one part of the chart.

A stellium is a cluster of three or more planets occupying the same zodiac sign or the same astrological house. There is some disagreement about the minimum count — some astrologers require four planets to call it a stellium, others accept three — but the principle is the same: an unusual concentration of planetary weight in one area of the chart.

A stellium produces a kind of gravitational pull on the personality. If you have four planets in Capricorn, the Capricorn themes (structure, ambition, responsibility, slow building) are likely to feel central to who you are, even if your rising sign and Sun sign are elsewhere. The same applies to a house stellium: four planets in the seventh house make partnership a defining axis of life regardless of how the rest of the chart looks.

Stelliums are interpreted as both a strength and a vulnerability. The strength is focus and depth in the area of life the stellium occupies. The vulnerability is overcommitment to that area at the expense of others, and a tendency to see the world through a single dominant lens.

When transits hit a stellium, they hit several planets at once. A Saturn transit to a Capricorn stellium activates four placements simultaneously rather than one, which intensifies the felt weight of the transit and tends to make these periods unusually significant for the chart owner.