Star cluster

Star clusters are large groups of <a href="/facts/Star/PFbd6ICx">stars</a> held together by <a href="/facts/Self-gravitation/JMNuzEYJ">self-gravitation</a>. Two main types of star clusters can be distinguished. <a href="/facts/Globular_cluster/FL0EERJU">Globular clusters</a> are tight groups of ten thousand to millions of old stars which are <a href="/facts/Gravitation/bqAN7DdQ">gravitationally</a> bound. <a href="/facts/Open_cluster/UodlJqcx">Open clusters</a> are more loosely clustered groups of stars, generally containing fewer than a few hundred members, that are often very young. As they move through the <a href="/facts/Galaxy/zCyUvEf7">galaxy</a>, over time, open clusters become disrupted by the gravitational influence of <a href="/facts/Giant_molecular_cloud/5jEwCJxs">giant molecular clouds</a>. Even though they are no longer gravitationally bound, they will continue to move in broadly the same direction through space and are then known as <a href="/facts/Stellar_association/urBqjfYg">stellar associations</a>, sometimes referred to as moving groups.
Star clusters visible to the naked eye include the <a href="/facts/Pleiades/tjwtx82z">Pleiades</a>, <a href="/facts/Hyades_(star_cluster)/XmNqJhqA">Hyades</a>, and <a href="/facts/47_Tucanae/mhw4MNTP">47 Tucanae</a>.

Star cluster open-in-new

Star cluster