star system
a grouping of two or more stars
binary stars
two stars within the same star system; other wise known as double stars
eclipsing binary stars
two stars within the same star system; one blocks the light of the other periodically
open cluster
a star cluster with a loose, disorganized appearance; no more than a few thousand stars
globular cluster
a large grouping of older stars; may contain over one million stars
galaxy
a large collection of singular stars, star systems, star clusters, dust and gas bound together by gravity
spiral galaxy
a galaxy with a bulge at its center and arms spiraling outwards from that bulge; similar to a pinwheel
elliptical galaxy
a galaxy that looks like a round or flattened ball
irregular galaxy
a galaxy with no definitive, regular shape
quasar
a young galaxy with a large black hole at its center
Milky Way
a spiral galaxy; the galaxy that we live in