AMagellanic spiral galaxy is aspiral galaxy with only onespiral arm. Magellanic spiral galaxies are classified as the typeSm (with sub-categoriesSAm,SBm,SABm); the prototype galaxy and namesake for Magellanic spirals is theLarge Magellanic Cloud, an SBm galaxy. They are usually smallerdwarf galaxies and can be considered to be intermediate betweendwarf spiral galaxies andirregular galaxies. They are found in proximity to larger spiral galaxies such as the Milky Way, as is the case with the LMC and the Small Magellanic Cloud (SMC).[1]
Magellanic spiral galaxies also have a stratified stellar structure;main sequence stars are found in their spiral arm, andsupergiants are clustered in a thick rectangular bar across the middle.[2]
SAm galaxies are a type ofunbarred spiral galaxy, whileSBm are a type ofbarred spiral galaxy.[3]SABm are a type ofintermediate spiral galaxy.
TypeSm andIm galaxies have also been categorized asirregular galaxies with some structure (typeIrr-1).[3] Sm galaxies are typically disrupted and asymmetric.[4]dSm galaxies aredwarf spiral galaxies ordwarf irregular galaxies, depending on categorization scheme.
The Magellanic spiral classification was introduced byGerard de Vaucouleurs, along withMagellanic irregular (Im), when he revamped theHubble classification of galaxies.
![[icon]](/mt/?noimg=&dark=on&url=http%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aWiki_letter_w_cropped.svg) | This sectionneeds expansion. You can help byadding missing information.(April 2010) |
| Example | Type | Image | Information and Notes |
|---|---|---|---|
| Magellanic Spirals | |||
| SAdm | |||
| NGC 5204 | SAm |  | Satellite of Pinwheel Galaxy |
| NGC 4676A | SABdm | .jpg) | Part of a galaxy merger, to the left of it is the galaxy NGC 4676B. |
| NGC 4625 | SABm |  | It has only one spiral arm. In ultraviolet it extends four times farther than in visible light. |
| NGC 4236 | SBdm |  | In M81 Group |
| Large Magellanic Cloud | SBm |  | Prototype galaxy for this galaxy class, and satellite of Milky Way |
| Sdm | |||
| Sm | |||
| Dwarf Magellanic Spirals | |||
| dSAdm | |||
| dSAm | |||
| dSABdm | |||
| dSABm | |||
| dSBdm | |||
| dSBm | |||
| dSdm | |||
| NGC 5474 | dSm |  | Satellite of Pinwheel Galaxy |
