The Milky Way is a barred spiral type of galaxy. In the Milky Way, there is a cluster of stars that form a dense, bar-shaped structure, and there is a spinning, flat disk structure that extends outward with the spiral arms. Also, there is a bulge of older stars in the Milky Way, and then there is the dark matter halo that surrounds the system. The diameter of the Milky Way ranges from 100,000 to 120,000 light-years.