NGC 4608 has a very well-defined bar. Surrounding the bar, there is an inner ring that is defined by a sharp inner edge. Outside of the inner ring,[5] there is a low surface brightness disk[6] that contains weak spiral features.[5]
The center of NGC 4608 is a classical bulge, which is a bulge similar to an elliptical galaxy.[2] The disk in NGC 4608 is practically considered non-existent. One explanation is that the bar in the galaxy was able to form without a disk. Another explanation says that a weak bar forms initially. Over time, the bar grows by causing the external disk to lose angular momentum therefore funneling material toward the bulge. Then the bar would be surrounded by a halo with very little or no disk left.[6]
