Introduction to Astrophysics/Galaxies:Shapes and Evolution/Irregular Galxies

Irregular galaxies have two types, classified by Edwin Hubble: type one are irregulars that have a single bar but did not have enough material to form into a spiral; type two are completely irregular galaxies, which have a lot of star formation. Irregulars are usually very small and have a lot of star formation (making pink colors), such as the Large and Small Magellanic Cloud, dwarf galaxies that are satellites of the Milky Way and are only a few thousand or more light years across.