The Hubble Classification, also known as the Hubble Sequence, is a widely recognized method for systematically categorizing galaxy morphology. Galaxies are classified into elliptical, lenticular, and spiral (or barred spiral) galaxies.
Galaxies with irregular shapes that do not fit into any categories are classified as irregular galaxies. While this classification can be used for most galaxies, some do not fit into any category, though they have regular shapes.
A ring galaxy is one of these. There are various theories about their origin, but one leading hypothesis asserts that ring galaxies originate from galactic interactions and mergers. The citizen science project GALAXY CRUISE, using vast cosmic images captured by the Subaru Telescope, regards ring galaxies as interacting.
Ring galaxies are rare and difficult to find. This galaxy features three rings, which is exceptionally rare and valuable to scientific research.