| Home. | Universe Galaxies And Stars Archives. | 
Universe Galaxies Stars logo.
     | Universe | Big Bang | Galaxies | Stars | Solar System | Planets | Hubble Telescope | NASA | Search Engine |

Dwarf galaxies hosts billions of stars in the universe.


Ten Years Since The Revolution at Amazon.

SAS Black Ops at Amazon.
Amazon Kindle EBook Reader: Click For More Information.

Dwarf galaxy is a small galaxy. A dwarf galaxy is composed of up to several billion stars, a small number compared to our own Milky Way's 200-400 billion stars. The Large Magellanic Cloud, containing over 30 billion stars, is sometimes classified as a dwarf galaxy while others consider it a full-fledged galaxy going around the Milky Way galaxy.

Dwarf Galaxy.
Image of the Phoenix Dwarf Galaxy.

Creation of dwarf galaxies.

Current theory believes most galaxies, including dwarf galaxies, form in association with dark matter or out of gas containing metals. However, NASA's Galaxy Evolution Explorer space probe identified new dwarf galaxies forming out of gases lacking metals. These galaxies were located in the Leo Ring, a cloud of hydrogen and helium around two massive galaxies in the constellation Leo.

Local dwarf galaxy.

There are many dwarf galaxies in the Local Group: these small galaxies frequently orbit around larger galaxies, such as the Milky Way, the Andromeda Galaxy and the Triangulum Galaxy. A recent paper has suggested that many dwarf galaxies were created by tidal forces during the early evolution of the Milky Way and Andromeda. Tidal dwarf galaxies are produced when galaxies collide and their gravitational masses interact. Streams of galactic material are pulled out away from the parent galaxies and the halos of dark matter that surround them.

The Milky Way has 14 known dwarf galaxies orbiting it, and recent discoveries have also led astronomers to believe the largest globular cluster in the Milky Way, Omega Centauri, is in fact the core of a dwarf galaxy with a black hole in its center, which was at some time absorbed by the Milky Way. (See Milky Way for more information.)

Dwarf galaxies come in many different morphologies.

  • Elliptical galaxy: dwarf elliptical galaxy (dE) and its subtype dwarf spheroidal galaxy (dSph).
  • Irregular galaxy: dwarf irregular galaxy (dI).
  • Spiral galaxy: dwarf spiral galaxy.

Hobbit Dwarf galaxy.

The recently coined term, hobbit galaxy has been used to describe galaxies smaller and dimmer than dwarf galaxies.

Ultra compact Dwarf galaxies.

Ultra Compact Dwarf galaxies (UCD) are a recently discovered class of very compact galaxies with very high stellar population counts. They are thought to be on the order of 200 light years across, with a hundred million stars. It is theorized that these are the cores of nucleated dwarf elliptical galaxies, that have been stripped of gas and outlying stars by tidal interactions, travelling through the hearts of rich clusters. UCDs have been found in the Virgo Cluster, Fornax Cluster, Abell 1689, Coma Cluster, amongst other clusters.

Partial list of dwarf galaxies.

  • Aquarius Dwarf..
  • Canis Major Dwarf Galaxy. .
  • I Zwicky 18. .
  • Irregular Galaxy IC 10. .
  • Large Magellanic Cloud. .
  • NGC 1569. .
  • NGC 1705. .
  • Pegasus Dwarf Irregular Galaxy. .
  • Phoenix Dwarf. .
  • Sagittarius Dwarf Elliptical Galaxy. .
  • Sagittarius Dwarf Irregular Galaxy. .
  • Sculptor Dwarf Galaxy. .
  • Sculptor Dwarf Irregular Galaxy. .
  • Sextans A. .
  • Sextans Dwarf. .
  • Small Magellanic Cloud. .
  • Tucana Dwarf. .
  • Ursa Minor Dwarf. .
  • Willman 1. .
  • Carina Dwarf. .
  • Draco Dwarf. .
  • Fornax Dwarf. .
  • Leo II (dwarf galaxy). .

  Go To Print Article  


Universe - Galaxies and Stars: Links and Contacts

the web this site
 | GNU License | Contact | Copyright | WebMaster | Terms | Disclaimer | Top Of Page. |