ABSTRACT
Most of the stars we observe are part of the Galaxy. The name Galaxy originated from the Greek word for milk (gala). We observe the Galaxy in the night sky as a Milky Way, or a bright strip, which represents a high concentration of stars. The general structure of the Galaxy is of a nucleus and a disk embedded in a low density spherical-like structure (spheroid). The solar system exists in the disk, at about three-fifths of its radius. We observe the bright strip of the Milky Way when we look in the direction of the plane of the disk. Looking in any direction other than that of the disk plane, we see a much lower density of stars.
