1. Types Of Star Clusters
There are three types of star clusters: open clusters, globular clusters, and stellar associations.
Open clusters are groups of stars that are loosely bound together by gravity. They are often found in the spiral arms of galaxies. Open clusters are typically young, with most stars less than 1 billion years old.
Globular clusters are groups of very old stars that are tightly bound together by gravity. Globular clusters are found in the halo of galaxies, which is the outermost part of the galaxy.
Stellar associations are groups of stars that are not as tightly bound by gravity as open clusters or globular clusters. Stellar associations are typically young, with most stars less than 100 million years old.
2. Formation Of Star Clusters
Star clusters form when a gas cloud collapses under its own gravity. As the gas cloud collapses, it begins to spin faster and faster. This causes the cloud to flatten into a disk. The disk of gas continues to collapse until the pressure and temperature are so high that nuclear fusion begins to take place. This causes the gas to start to glow, and the disk becomes a star cluster.
3. Properties Of Star Clusters
Star clusters have many properties in common.
All star clusters are held together by gravity.
All star clusters have a similar age.
All star clusters have a similar size.
All star clusters have a similar composition.