spherical component

The space above and below the disk of the Galaxy is occupied by a thinly populated extension of the central bulge. Nearly spherical in shape, this region is populated by the outer globular clusters, but it also contains many individual field stars of…

Most and perhaps all galaxies have a spheroidal component of old stars. In the ellipticals this component constitutes all or most of any given system. In the spirals it represents about half the constituent stars (this fraction varies greatly according to galaxy type).…