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# Galaxies

Its really quite hard to realize how big the universe is! It’s composition, its size and so many stuffs. This universe carrying large number of galaxies and each galaxies carrying millions of stars all bound by a unique force known as gravitational force. Here our sun is just a star and we stay in a galaxy. There lies our solar system where our earth lies. Let’s see little more about galaxy in this page.

The Galaxy is a part of universe that comprises of collection of billions of stars, dust and gas that are bound by the gravitational force. It’s even studied that there are approximately 70,000 million or even more stars in universe.  There are many galaxies existing in the universe. The solar system in which our earth stands is in Milky Way galaxy.

## Types

Galaxies vary a lot in shapes, size, color and composition. If we go for their shapes they are of three types:

1) Elliptical Galaxies
2) Spiral Galaxies
3) Irregular Galaxies

Elliptical Galaxies shapes more like a elongated sphere. Well known Andromeda galaxy is one which shapes so.

Spiral Galaxy has lot more of sections that relys of components - bulge, disk and the halo. The M100 and M83 are the spiral galaxies examples.

Irregular Galaxies has no formal regular shape or any structure. The Irr I and Irr II are some examples.

## Names

The galaxy scale varies from one galaxy to other. The Milky way is approximately 10,000 light years and of 9.25 $\times$ 1017 km in diameter. The Andromeda Galaxy which is next to milky way galaxy is of 260,000 light years and has the diameter of 2.4 $\times$ 1019 km. The popular largest galaxies are IC 1101, NGC 262, BCG of Phoenix Cluster etc which has size of (2.2-2.8) $\times$ 106 light years.