Bar galaxies are unique spiral galaxies.
They differ from other spiral galaxies in that have nuclei that are shaped like bars instead of spheres. As with many objects in the universe barred galaxies are not fully understood. No one is exactly sure why these galaxies have bars or how they form. There are also many theories as to what happens inside of these bars. The subject of barred galaxies hits close to home since many scientists now believe that our own galaxy, the Milky Way, is a barred.