The Stars - Zoom Astronomy Search the Web. Search the Web with our sponsor, Overture. Each star in the sky is an enormous glowing ball of gas. Our sun is a medium-sized star.
Stars can live for billions of years.
In the universe, most stars occur in groups of at least two stars. About half of all stars are in a binary star system. These remote objects lie mostly around the central bulge of spiral galaxies. There are larger groups of stars, called clusters . These are relatively unorganized collections of stars.