The peculiar galactic pair, dubbed Arp 116, is comprised of a giant elliptical galaxy known as Messier 60 and a much smaller spiral galaxy named NGC 4647, the European Space Agency/Hubble Information Center in Garching, Germany, reported Thursday.
M 60 is very bright, noticeably larger than its neighbor, and has a far higher mass of stars.
Like other elliptical galaxies, M 60 has a golden color because of the many old, cool and red stars in it, while NGC 4647 has many young and hot stars that glow blue, giving the galaxy a noticeably different hue.
Although they overlap as seen from Earth, there is no clear evidence they are actually interacting, which would normally result in a sudden burst of new stars being formed, astronomers said.
However, they said, studies of very detailed Hubble images suggest the beginning of some tidal interaction between the two.
Since the two galaxies are neighbors, we see them at the same scale, making Hubble's portrait a textbook example of how giant elliptical galaxies differ in size, structure and color from their smaller spiral cousins.