Stellium — Astrology glossary

A stellium is a cluster of three or more planets grouped closely together, usually within a single sign or house, sometimes both. Definitions vary: some astrologers require four planets, and some count the Sun and Moon while others restrict it to planets. The effect is concentration. In a natal chart a stellium matters because it heavily weights one part of the chart, often making the themes of that sign or house dominate the personality at the expense of balance elsewhere. For example, someone with the Sun, Mercury, and Venus all in Scorpio in the tenth house is read as channelling intensity, privacy, and depth into their career and public role, sometimes so single-mindedly that other areas of life feel neglected. The grouped planets tend to act together, reinforcing one another.