open clusters

Open clusters are groups of stars that formed from the same cloud of gas and dust, resulting in stars that are roughly the same age and composition. These clusters are loosely bound by gravity, meaning their stars can eventually drift apart over time. They are typically found in the spiral arms of galaxies, including our Milky Way, and often contain a few dozen to a few thousand stars. Open clusters are important for studying stellar evolution because their stars are formed at the same time, allowing scientists to compare how different stars develop under similar conditions.