Spiral Galaxy

Spiral galaxies are named to the spiral structures that extend from the center into the particular disk. A spiral galaxy is a certain kind involving galaxy originally referred to by Edwin Hubble throughout his 1936 perform The Realm of the Nebulae and, as such, forms part of the Hubble sequence. Spiral galaxy incorporate a flat, rotating disc containing superstars, gas and airborne dirt and dust, and a core concentration of stars often known as the bulge.