Astronomers have discovered a unique collisional ring galaxy, nicknamed the "Bullseye," that features nine rings, the most observed in a collisional ring galaxy to date.
Observations show Andromeda has a more active star formation history than the Milky Way, potentially due to a past galactic collision. NASA recently released images of the Andromeda galaxy ...
While eight rings around the galaxy were discovered by the Hubble Telescope, astronomers confirmed a ninth ring using data from the WM Keck Observatory in Hawaii.