Astronomers trace the striking pattern to an encounter between a big galaxy and a much smaller one some 50 million years ago.

Around 50 million years ago, a blue dwarf galaxy shot through the center of an enormous galaxy more than twice the size of the Milky Way, called LEDA 1313424. Now, astronomers have revealed the ...

A blue dwarf galaxy pitched through the bullseye's galactic neighborhood 50 million years ago, leaving behind nine glittering rings.