Topic
Star Clusters
4 questions tagged Star Clusters — spanning every one of the seven Ws.
what
What is a globular cluster?
A globular cluster is a tightly packed spherical group of very old stars orbiting a galaxy. Some globular clusters contain hundreds of thousands or even millions of stars.
AstronomyStar Clusters
why
Why do stars in a cluster all seem to be about the same age?
Star clusters usually form from the same cloud of gas over a relatively short period of time. That gives the stars a similar age and chemical makeup.
StarsStar clusters
which
Which star cluster is the oldest known globular cluster?
The globular cluster NGC 6397 is one of the oldest known star clusters, at about 13 billion years old. It formed very early in the history of the Milky Way.
AstronomyStar Clusters
how
How do globular clusters survive for billions of years?
Their stars are tightly bound by gravity in compact, dense spheres. Even though stars move around inside them, the cluster as a whole can remain stable for a very long time.
SpaceStar Clusters