Globular clusters

Globular cluster Omega Centauri is thought to contain about ten million stars. These ancient objects may not be as old as once thought. Credit: ESO

Gallery Omega Centauri globular cluster

M13 Great Hercules Cluster by Mark Griffith, Swindon, Wiltshire, UK. Equipment: Teleskop service 12

Gallery Hercules Globular Cluster

Located in the constellation of Pegasus, 35,000 lightyears away, M15 is one of the oldest-known globular clusters – dating back 12 billion years. Hubble captured the swarming hot blue and cooler golden stars that become more concentrated towards M15’s bright core. Credit: ESA, Hubble, NASA

Observing guide Globular clusters

Globular cluster NGC 6397, as seen by the Hubble Space Telescope.

Concentration of black holes found in ancient star cluster

Composite image of the globular cluster NGC 3201, obtained with the WFI instrument on the ESO/MPG 2.2-m telescope at La Silla. Image Credit: ESO

Strange star reveals black hole in cluster