Contents:

Introduction  Disk  Bulge  Halo

Introduction:
The Milky Way is a gravitationally bound collection of about one hundred billion stars.
Our Sun is one of these stars and is located roughly 24,000 light years (One light year is about 5,680,368,000,000 miles) from the center of our the Milky Way.
The Galaxy has three major components: a disk, in which our solar system resides, a bulge at the centre of the galaxy, and a surrounding halo.

Disk:
A thin disk consisting of young and intermediate age stars, this disk also contains gas and is actively forming new stars. Dust in the disk absorbs blue light more than red light and makes stars appear more reddish. The disk of the Milky Way has four spiral arms. These spiral arms are regions of active star formation.

Bulge:
The bulge is a flattened spheroid of dimension at the center of the galaxy. This is a high density region where stars tend to be red and are very old.

Halo:
Surrounding the disk is an extended dark halo whose composition is unknown. The halo is believed to be composed mainly of dark matter which may extend well beyond the edge of the disk. Since the matter in the halo does not consist of luminous stars, it does not show up in visible light images. The existence of the dark halo is inferred from its gravitational pull on the visible matter.