center of the galaxy. stars are in elliptical orbits with random orientation. They tend to have metallicity and tend to be tend to They Population stars bob up and down in the disk while orbiting the center. They tend to have metallicity and tend to be They tend to belong to Population although there can be a mix of stars of different ages and colors in that region. The oldest and most metal-poor stars are the Population stars wi? very hard to discover. disk halo and bulge disk, halo, and bulge low medium high younger and bluer older and redder all bright yellow supergiants pretty much average in size and age I II III