A Magellanic spiral galaxy is a spiral galaxy with only one spiral arm. Magellanic spiral galaxies are classified as the type Sm (with sub-categories SAm, SBm, SABm); the prototype galaxy and namesake for Magellanic spirals is the Large Magellanic Cloud, an SBm galaxy. They are usually smaller dwarf galaxies and can be considered to be intermediate between dwarf spiral galaxies and irregular galaxies.

Magellanic spirals

SAm galaxies are a type of unbarred spiral galaxy, while SBm are a type of

barred spiral galaxy A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars. Bars are found in about two thirds of all spiral galaxies in the local universe, and generally affect both the motions of stars and interstellar gas ...

. Linda S. Sparke, John Sill Gallagher, ''Galaxies in the Universe: An Introduction'', 2ed., Cambridge University Press, 2007, SABm are a type of intermediate spiral galaxy. Type ''Sm'' and ''Im'' galaxies have also been categorized as irregular galaxies with some structure (type Irr-1). Sm galaxies are typically disrupted and asymmetric. dSm galaxies are dwarf spiral galaxies or dwarf irregular galaxies, depending on categorization scheme. The Magellanic spiral classification was introduced by Gerard de Vaucouleurs, along with Magellanic irregular (Im), when he revamped the Hubble classification of galaxies.

Grades of Magellanic spiral galaxies

List of Magellanic spirals

Barred (SBm)

* Large Magellanic Cloud (LMC; prototype galaxy) * Small Magellanic Cloud (SMC) * NGC 1311 * NGC 4618University of Wisconsin
BARRED MAGELLANIC SPIRALS
(accessed 1 March 2009) * NGC 4236 * NGC 55 * NGC 4214 * NGC 3109 * IC 4710

Intermediate (SABm)

* NGC 4625 * NGC 5713

Unbarred (SAm)

* NGC 5204NASA/IPAC Extragalactic Database
/ref> * NGC 2552

References

{{DEFAULTSORT:Magellanic Spiral * * Galaxy morphological types