Irregular Galaxies (“Irr”)
An irregular galaxy is neither a spiral nor an elliptical. Irregular galaxies tend to
be smaller objects without definite shape, and they typically have very hot newer
stars mixed in with lots of gas and dust. These galaxies often have active regions
of star formation. Sometimes their irregular shape is the result of interactions or
collisions between galaxies. Observations such as the Hubble Deep Fields show
that irregular galaxies are more common in the distant (early) universe.