Those stars that are found in the halo of our Galaxy and in its central bulge. The stars in the galactic halo, including globular clusters, describe highly elliptical orbits around the Galaxy’s centre. Members of Population II have a significantly lower content of heavy elements than stars of Population I. It is believed that Population II stars formed in the first billion years or so of the Galaxy’s life, before the formation of the galactic disk. See also halo population.