polar-ring galaxy

The event likely took place at least 2-3 billion years in the past, and may have resembled the processes that form polar-ring galaxy.

While these galaxies have been extensively studied, many other polar-ring galaxies have since been identified.

One possibility is that a material is tidally stripped from a passing galaxy to produce the polar ring seen in the polar-ring galaxy.

A polar-ring galaxy is a type of galaxy in which an outer ring of gas and stars rotates over the poles of the galaxy.

The best-known polar-ring galaxies are S0s (lenticular galaxies), but from the physical point of view they are part of a wider category of galaxies, including several ellipticals.