Clusters

In astronomy a cluster usually refers to a group of stars that were born at roughly the same time and are still bound by gravity. Star clusters come in two flavors: open and globular.

Getting Started

Bright open clusters are easy to observe with binoculars. The Pleiades cluster (M45) is visible to the naked eye in almost any cloud-free sky. Other good open clusters for beginners include the Beehive Cluster (M44), the Wild Duck Cluster (M11), and the Double Cluster.

Bright globular clusters are also fairly easy to spot. For mid-Northern latitudes the easiest globulars include the Hercules globular cluster (M13), M2, M3, M5, and M22.