The first polar-ring elliptical galaxies were identified in 1978. They were NGC 5128, NGC 5363, NGC 1947 and Cygnus A, while the polar-ring S0 galaxies NGC 2685 and NGC 4650A were at that time indicated as resulting from similar formation processes.
In 1978, astronomers first encountered a group of elliptical galaxies characterized by their ring-like structures. These included NGC 5128, NGC 5363, NGC 1947, and Cygnus A, as well as two S0 galaxies, NGC 2685 and NGC 4650A, which were believed to have formed through similar mechanisms.