# Galaxy group & cluster

Also called: galaxy cluster, compact group.

Galaxies bound together by gravity: a few in a group, hundreds to thousands in a cluster.

Galaxies rarely live alone. Our [milky way](https://astropilot.space/glossary/milky-way) and Andromeda belong to the Local Group of about 80 galaxies. Larger clusters, like the Virgo Cluster 55 million light-years away, hold more than a thousand.

Compact groups — Stephan's Quintet, Seyfert's Sextet — pack several galaxies into a field smaller than the Moon, and some are colliding.

**At the eyepiece:** Compact groups are tiny and faint: high power and a large aperture help. The Virgo Cluster's brightest members (M 84, M 86, M 87) fit in one low-power field.

**Examples:** [HCG92](https://astropilot.space/object/HCG92.md), [HCG79](https://astropilot.space/object/HCG79.md), [NGC4676](https://astropilot.space/object/NGC4676.md), [M86](https://astropilot.space/object/M86.md)

**Related:** [Galaxy](https://astropilot.space/glossary/galaxy.md), [Elliptical galaxy](https://astropilot.space/glossary/elliptical-galaxy.md)

From the AstroPilot astronomy glossary: https://astropilot.space/glossary/galaxy-group