Stellar populations. Credit: University of Hertfordshire.
So-called thin disk stars, such as the Sun or Alpha Centauri, lie at a typical distance of about 1,000 light-years from the galactic midplane. Thick disk stars, on the other hand, such as Lalande 21185, tend to have higher velocities out of the galactic plane and lie at an average distance of about 3,500 light-years from the midplane.
Beyond the limits of the Galaxy's thick disk is the galactic halo.