What are the basic characteristics of stellar orbits in the bulge, disk, and halo of our galaxy?

1 Answer
Oct 14, 2017

The stellar orbits become progressively less organized as we go from disk, to bulge, to halo


The disk orbits are more or less circular and all lie nearly on a plane. The disk stars orbit in circles with the same orientation, except for little up- and- down motion.

The halo and bulge orbits are much less organized: they vary from round to very elliptical, and don't lie on a plane either. The stars travel in elliptical paths with random orientations. The halo stars travel high above and far below the disk.