Milky Way galaxy. Computer artwork of the Milky Way galaxy, which contains our solar system. The Milky Way is a spiral galaxy. It has a nucleus (yellow) of old stars at its centre. Around this nucleus, but 10,000 to 16,000 light years away, is a bright 'molecular ring' of young hot stars and star forming regions. The spiral arms extend outwards from this ring. The total diameter of the galaxy is thought to be 100,000 light years.