Birth Chart Basics
A stellium is three or more planets in the same sign or the same house. It concentrates a large part of the chart into one area of life, which tends to make that area unusually loud and the...
Three planets in one sign or house is the common threshold; some practitioners insist on four, and some only count it if the Sun or Moon is among them. There is no authority to settle this, and the disagreement tells you something useful: a stellium is a description of emphasis, not a category with a hard edge.
What matters more than the count is which planets. Three outer planets in a sign is a generational pattern shared by everybody born across several years. Three personal planets in one house is genuinely yours.
A stellium in a sign means a lot of the chart behaves the same way. A stellium in a house means a lot of the chart happens in the same area of life. They often coincide and they are not the same statement.
The house version is the more personal one, because houses depend on a birth time and signs mostly do not. A stellium in Capricorn is shared with everybody born that month. A stellium in your 7th house is not.
The usual report is a life that keeps returning to one subject, often to the point of imbalance, and a corresponding blankness somewhere else. People with a 10th house stellium tend to have careers that swallow everything. People with a 4th house stellium tend to have family situations that do.
The opposite house is worth looking at. A stellium puts weight on one end of an axis, and what is underfed at the other end is usually the thing that eventually demands attention.
| Made of | How personal | What it means |
|---|---|---|
| Sun, Moon, Mercury, Venus, Mars | Yours alone | A genuine concentration in your own chart |
| Jupiter and Saturn | Shared with months of births | Social rather than personal emphasis |
| Uranus, Neptune, Pluto | Shared with years of births | Generational. Almost everybody your age has it |
| Any three in one house | Depends on your birth time | The most personal kind, and the most useful |
Four planets in the 10th house is the easiest one to recognise from outside: a person whose career is not a part of their life but the frame the rest hangs on, often from much younger than is usual, and usually at a visible cost to the 4th house at the other end, which is home.
The same four planets in the 4th produces the mirror image: somebody organised around family and private life, for whom public standing never quite becomes interesting. Neither is better. Both are lopsided, which is what the word means.
how to read a birth chart, then why empty houses are normal, then how to find your birth time.
Everything on this page is general by necessity. A reading built from your own date, time and place is the version that names your placements rather than describing the categories they fall into. If you do not know your birth time, this covers how to find it.
Three or more in the same sign or house, on the most common definition. Some practitioners require four.
Sign stelliums are common because the slow planets cluster for years at a time. House stelliums are more individual.
Neither. It describes concentration, which is an advantage in the area concerned and a cost everywhere else.
RubyAstro writes about astrology for reflection and self-understanding. Nothing here is medical, legal or financial advice, and none of it is a prediction of events. Read our full disclaimer.
Finding Your Birth TimeIf you were born in the US between 1945 and 1991, there is a real chance your birth time was recorded under a daylight saving rule your chart calculator does not know about. Here is how to check.
Finding Your Birth TimeMost of your chart does not need the hour. Every planet except the Moon stays in the same sign all day, and so does every aspect between them. Here is exactly what you keep, what you lose, and what to do about the gap.
Planets in SignsSun governs identity and purpose, and Aries is a fire sign in cardinal mode. Sun is in exaltation here. Here is what the placement does, its shadow, and the real dates Sun is in Aries.
Birth Chart BasicsRead a chart in four passes: the Big Three first, then which planets sit in which houses, then the aspects between them, then the chart as a whole. Most people fail at charts because they start...
Birth Chart BasicsA birth chart is a diagram of where the Sun, Moon and planets were, as seen from your exact birthplace, at the exact moment you were born. It is astronomy: the positions are calculated and...
Birth Chart BasicsAn empty house is normal and means nothing is missing. There are ten bodies and twelve houses, so at least two houses are empty in every chart and most charts have five or six. An empty house is...