older stars inhabiting mainly the central and halo portions of the Galactic system.

The class of stars with relatively low abundances of heavy elements. These stars are generally found in a spheroidal distribution about the galactic center and throughout the halo, and are relatively old.

Old stars with relatively low abundances of metals, found in the nuclear bulge of a galaxy or in globular clusters.

(stars): older, redder stars that have very elliptical orbits randomly oriented and are found in the stellar halo and bulge of the Milky Way Galaxy.

the stars making up globular clusters, the bulges and halos of spiral galaxies, and all elliptical galaxies: characterised by great age (star formation ceased 109 y ago), so that there are no blue supergiants or upper main sequence stars and the brightest stars are red giants; generally thought of as being low in heavy elements, but strictly this is true only of the halo, not of the bulge nor of large elliptical galaxies.

Stars poor in atoms heavier than helium. Nearly always relatively old stars found in the halo, globular clusters, or the nuclear bulge.