Dwarf galaxy facts for kids
A dwarf galaxy is a small galaxy that has only a few billion stars. This is much fewer than our own Milky Way galaxy, which has 200 to 400 billion stars! The Large Magellanic Cloud is a good example. It has over 30 billion stars and sometimes people call it a dwarf galaxy. Other times, they call it a regular galaxy that orbits the Milky Way.
How Dwarf Galaxies Form
Most galaxies, including dwarf galaxies, usually form near something called dark matter. They can also form from gas that has metals in it. However, NASA's Galaxy Evolution Explorer space probe found new dwarf galaxies forming in a different way. These galaxies grew from gases that did not have metals. They were found in the Leo Ring, a big cloud of hydrogen and helium gas. This cloud is around two huge galaxies in the Leo constellation.
Sometimes, dwarf galaxies can get too close to bigger spiral galaxies. The strong pull of gravity from the larger galaxy can pull the dwarf galaxy apart. Eventually, the dwarf galaxy might even merge with the bigger one.
Dwarf Galaxies Near Us
There are many dwarf galaxies in our own Local Group of galaxies. These small galaxies often orbit around larger ones. For example, they orbit the Milky Way, the Andromeda Galaxy, and the Triangulum Galaxy. Scientists think that many dwarf galaxies were created long ago. This happened when the Milky Way and Andromeda galaxies pulled on each other with tidal forces.
Tidal dwarf galaxies form when galaxies crash into each other. Their gravity pulls streams of material away from the main galaxies. These streams can then form new dwarf galaxies.
The Milky Way has more than 20 known dwarf galaxies orbiting it. Recent observations suggest that Omega Centauri, the largest globular cluster in the Milky Way, might actually be the center of a dwarf galaxy. This dwarf galaxy might have a black hole in its middle. It was likely absorbed by the Milky Way a long time ago.
Images for kids
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The Large Magellanic Cloud, a satellite galaxy of the Milky Way
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Dwarf galaxies like NGC 5264 typically possess around a billion stars.
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The Phoenix Dwarf Galaxy is a dwarf irregular galaxy, featuring younger stars in its inner regions and older ones at its outskirts.
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UGC 11411 is a galaxy known as an irregular blue compact dwarf (BCD) galaxy.
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Blue compact dwarf PGC 51017.
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LEDA 677373 is located about 14 million light-years away.
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Dwarf galaxy DDO 68.
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Dwarf galaxy UGC 685 taken by Hubble.
See also
In Spanish: Galaxia enana para niños
