Irregulars and Dwarfs

Irregular galaxies have no defined shape — they are chaotic collections of stars, gas, and dust. Many are the result of gravitational interactions with larger neighbors. The Large and Small Magellanic Clouds, visible from the Southern Hemisphere, are irregular dwarf galaxies orbiting the Milky Way.

Dwarf galaxies are the most common type in the universe but the hardest to detect because of their low luminosity. The Milky Way has over 50 known satellite dwarf galaxies. Some contain only a few thousand stars.