Irregular galaxy

[1] Irregular galaxies do not fall into any of the regular classes of the Hubble sequence, and they are often chaotic in appearance, with neither a nuclear bulge nor any trace of spiral arm structure.

This makes irregular galaxies prime areas to study star formation without the effects of density waves.

Irregular galaxies may contain abundant amounts of gas and dust.

Due to their small sizes, they are prone to environmental effects like colliding with large galaxies and intergalactic clouds.

[13] The Small Magellanic Cloud remains classified as an irregular galaxy of type Im under current galaxy morphological classification, although it does contain a bar structure.