Open clusters are groups of stars that are loosely bound together by gravity. They typically contain a few dozen to a few thousand stars that formed from the same giant molecular cloud. Because they are relatively young, many of the stars in an open cluster are still in the early stages of their life cycles, making them interesting objects for astronomers to study. These clusters are often found in the Milky Way and can be observed with small telescopes. Famous examples include the Pleiades and Hyades clusters. Over time, the stars in an open cluster may drift apart as they interact with other stars and the gravitational forces of the galaxy.