Polar ring galaxy

Polar-ring galaxies are called that because their disks are aligned with the short axis of their central bulges, generally perpendicular to their long axis. The dynamically interesting feature they have is that their disk then samples the graviational potential in the polar plane of the bulge, rather than the equitorial like practically all other galaxies. Comparing velocities of the disk (or ring) to the bulge velocities gives us a handle on the shape of the halo of the galaxy, assuming that's what dominates the gravitional potential. Our results indicate that most such halos are near-spherical, but we do not have a large sample.