Milky Way. Optical image of the Milky Way, from the northern constellation of Perseus (top centre) to that of Cygnus (bottom centre). The Milky Way is the spiral galaxy in which our solar system is located. From our position, thought to be about twothirds out from its centre, along a small spiral arm, we view the galactic disc as a band of stars across the night sky. The Milky Way is thought to contain at least 100 billion stars.
