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Cool image time! The photo to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope, and appears part of a long term survey of nearby ringed galaxies. From the caption:

MCG+07-07-072 has quite an unusual shape, for a spiral galaxy, with thin arms emerging from the ends of its barred core to draw a near-circle around its disc. It is classified, using a common extension of the basic Hubble scheme, as an SBc(r) galaxy: the c denotes that its two spiral arms are loosely wound, each only performing a half-turn around the galaxy, and the (r) is for the ring-like structure they create. Rings in galaxies come in quite a few forms, from merely uncommon, to rare and astrophysically important!

Lenticular galaxies are a type that sit between elliptical and spiral galaxies. They feature a large disc, unlike an elliptical galaxy, but lack any spiral arms. Lenticular means lens-shaped, and these galaxies often feature ring-like shapes in their discs. Meanwhile, the classification of “ring galaxy” is reserved for peculiar galaxies with a round ring of gas and star formation, much like spiral arms look, but completely disconnected from the galactic nucleus – or even without any visible nucleus! They’re thought to be formed in galactic collisions.

This galaxy is about 320 million light years away, and is also known as Abell 426. Though astronomers think that these various shapes of galaxies, from barred to lenticular to ringed, are formed from a variety of galactic collusions and interactions with each galaxy’s nucleus, that remains nothing more than an educated guess. The complexity of galaxy evolution, involving billions of years and millions of stars, is barely in its infancy, and requires a lot of assumptions because our observations only involves a mere nanosecond in that grand history.