A stellium is a group of three or more planets in the same sign or the same house of a birth chart. It shows where a lot of your chart's energy is concentrated. Astrologers read that sign or area of life as a major theme, sometimes stronger than your Sun sign alone.
The simplest definition is three or more planets in one sign. Many astrologers also count three or more planets in one house. A stellium by house needs an accurate birth time, while one by sign does not.
Definitions vary at the edges. Some astrologers want four planets, not three. Some count the Sun and Moon but leave out points like the lunar nodes, Chiron or the rising degree. Others want the planets fairly close together, within about 10 to 15 degrees.
None of these is the one right rule. The general idea is the same: a crowd of planets in one place draws attention.
Each planet stands for a different part of you. The Sun is identity, the Moon is feeling, Mercury is thinking, Venus is love and taste, Mars is drive. When several of them sit in one sign, they all speak with that sign's accent.
So the sign's style shows up in many areas at once. It is not just how you see yourself, but also how you talk, love and act. That makes the theme hard to miss, both for you and the people around you.
A stellium can also leave other parts of the chart quieter by comparison. That is not a lack. It just means your focus tends to pull toward one place.
Say your Sun, Mercury and Venus are all in Virgo. That is a common stellium, because Mercury and Venus never stray far from the Sun.
Virgo likes precision, usefulness and getting details right. With your identity, your thinking and your affection all in Virgo, that care shows up everywhere. You might show love by fixing a friend's résumé. You might think in lists. You might feel most yourself when something works smoothly because of you.
The shadow side is the same trait pushed too far. A crowded Virgo can slide into worry or constant self-correction. Seeing the pattern clearly is often the first step toward easing it.
A stellium in a sign describes a style: how you do things. A stellium in a house describes a place: which part of life gets the attention.
For example, three planets in the tenth house point toward career and public life. Three planets in the fourth point toward home and family. Three in the seventh put partnerships at the center.
Often the two overlap. A stellium in Capricorn in the tenth house doubles down on ambition and structure. If the sign and house point in different directions, astrologers read the mix. Imagine a Sagittarius stellium in the fourth house: an adventurous spirit that still centers life on home.
A conjunction is an aspect between two planets that sit very close together, usually within about 8 degrees. A stellium is a larger cluster of three or more planets sharing one sign or house.
The two can overlap, but not always. Three planets in Leo at 1, 14 and 28 degrees form a stellium by sign. Yet the first and last are 27 degrees apart, so they are not conjunct.
It works the other way too. A planet at 29 degrees Taurus and one at 2 degrees Gemini are only 3 degrees apart. They form a tight conjunction, even though they sit in different signs. Close stelliums, where the planets are also conjunct, tend to feel the most unified.
The element of the sign sets the basic tone of a stellium.
If your stellium is in a different element from your Sun, you may feel pulled between two styles. Many people describe that as having a public self and a private one.
A stellium does not make you a stereotype of the sign. Your Moon, rising sign and aspects still add their own colors.
A stellium made only of Uranus, Neptune and Pluto is shared by everyone born over several years. Astrologers treat that as a generation theme. It feels personal mainly when it touches your Sun, Moon or angles.
An empty area of the chart is not a missing part of life either. The guide to empty houses covers why.
Look at your chart and count the planets in each sign. Any sign with three or more is a stellium by sign. With a birth time, do the same for each house.
Then ask where your energy tends to pool in daily life, and whether it matches. You can see your own birth chart and count the clusters for yourself.
Most astrologers say three or more planets in one sign or house. Some require four, and some also want the planets within about 10 to 15 degrees of each other.
Not especially. Mercury and Venus always travel near the Sun, so a Sun, Mercury and Venus stellium in one sign is fairly common. Stelliums of four or more planets are less common.
Usually yes. Most astrologers count the Sun and Moon. Points such as the lunar nodes, Chiron and the rising degree are more often left out.
It can be as important. If several planets sit in a sign that is not your Sun sign, that sign may describe you as much as your Sun does.