This new image from NASA’s Hubble Space Telescope shows ESO 185-IG013, a bright blue compact galaxy (BCG). BCGs are nearby galaxies with intense star formation. They are extremely blue in visible light, distinguishing them from other high-rise starburst galaxies that emit more infrared light. Astrophysicists study BCGs because they provide a relatively close equivalent to galaxies in the early universe. This means BCG can help scientists learn about the formation and evolution of galaxies that may have formed billions of years ago.

Hubble imaged ESO 185-IG013 in ultraviolet, visible and infrared to reveal details about its history. The galaxy is filled with hundreds of young star clusters, most of which are younger than 100 million years. Many star clusters are only 3.5 million years old, which is relative compared to the time scale of our universe. Scientists predict that many of these youngest clusters will not last long, as young clusters can often die after expelling too much gas. The abundance of young star clusters indicates that this galaxy is part of a recent galaxy collision and merger. Another feature is the irregular structure of the galaxy, probably resulting from the violent interaction of gas and dust during the collision. The merger provided the system with abundant fuel for star formation, which continues today.

ESO 185-IG013 also contains a tidal envelope, a diffuse glow surrounding its bright center that is a common signature of merging galaxies. Scientists believe that during a galactic merger, the smaller of two interacting galaxies is torn apart by the larger galaxy and loses most of its material. This releases material that is pulled back by the gravity of the larger galaxy. The dense region through which material moves is called the envelope and contains numerous star clusters. In addition to its shell, ESO 185-IG013 also has a northeastward gas tail.

The total mass of all stars in the system is more than 7 billion times that of our Sun. The system is located approximately 260 million light-years away from us.