extragalactic nebula, galaxy - (astronomy) a collection of star systems; any of the billions of systems each having many stars and nebulae and dust; "`extragalactic nebula' is a former name for `galaxy'"

heliosphere - the region inside the heliopause containing the sun and solar system

Crux, Crux Australis, Southern Cross - a small conspicuous constellation in the southern hemisphere in the Milky Way near Centaurus