The oldest stars in our Galaxy have different chemical compositions to younger ones. They are more primitive even than objects in the distant parts of the universe at redshifts z = 3-5; they are the oldest objects known. By observing them, OU astronomers are uncovering the formation and evolution of the Milky Way Galaxy, and the transformation of matter from the Big Bang into the stars that light up the Galaxy we live in.

The structure of the Galaxy
The concentration of the Milky Way into a band across a dark night sky tells us that most of the stars in our Galaxy are confined to a plane --- the Galactic disk --- within which we reside. The band reaches maximum brightness in the constellations of Sagittarius and Scorpio; in that direction lies the heart of the Galaxy.