<p>A stellar association is a loose cluster of stars, that formed at the same time from the same molecular cloud, and so have the same proper motion. Unlike open clusters, they are not gravitationally bound together, so the stars in a stellar association will gradually separate, forming a moving group of stars.</p>

<p>An example is the <a href="https://en.wikipedia.org/wiki/Scorpius%E2%80%93Centaurus_Association" rel="nofollow">Scorpius–Centaurus Association</a></p>

CC BY-SA 3.0
2015-11-07T22:13:43.467Z
The division between "cluster" and "association" is far from settled.
ProfRob
CC BY-SA 3.0
2015-11-07T15:36:14.953Z
2015-11-07T15:36:14.953Z
James K
<p>What exactly is a "stellar association" in the strict kinematic sense? </p>

CC BY-SA 3.0
2015-11-10T08:04:01.523Z
In what way does the [Wikipedia article](https://en.wikipedia.org/wiki/Stellar_kinematics#Stellar_associations) not help? "_A stellar association is a very loose star cluster, whose stars share a common origin, but have become gravitationally unbound and are still moving together through space. Associations are primarily identified by their common movement vectors and ages. Identification by chemical composition is also used to factor in association._" memberships."
Warrick
<star-cluster>
What exactly is a stellar association?
MichaelJRoberts
# What exactly is a stellar association?

(Asked by: username_0 on 2015-11-07)

What exactly is a "stellar association" in the strict kinematic sense?

**Tags:** star-cluster
> **Comments:**
> **username_1**: In what way does the [Wikipedia article](https://en.wikipedia.org/wiki/Stellar_kinematics#Stellar_associations) not help? "_A stellar association is a very loose star cluster, whose stars share a common origin, but have become gravitationally unbound and are still moving together through space. Associations are primarily identified by their common movement vectors and ages. Identification by chemical composition is also used to factor in association._" memberships."  

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## 1 answers

### Answer by username_2 on 2015-11-07. Score: 2 | Accepted answer

A stellar association is a loose cluster of stars, that formed at the same time from the same molecular cloud, and so have the same proper motion. Unlike open clusters, they are not gravitationally bound together, so the stars in a stellar association will gradually separate, forming a moving group of stars.

An example is the [Scorpius–Centaurus Association](https://en.wikipedia.org/wiki/Scorpius%E2%80%93Centaurus_Association)

> **Comments:**
> **username_3**: The division between "cluster" and "association" is far from settled.  

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