This cluster of galaxies was documented as a single cluster when it was first discovered, but later research revealed that there are actually two clusters. NASA @NASAHubble detected this double cluster of brightly glowing galaxies in the constellation Eridanus. One of the groups is about 2.3 billion light-years away, while the other, included in the Large Cluster Survey, is about 5.4 billion light-years from Earth. These two groups are known to have 30 trillion and 120 trillion times the mass of our Sun, respectively.

Image description:
A cluster of galaxies centred around what appears to be two large elliptical galaxies. The rest of the black background is covered by smaller galaxies of all shapes and sizes. In the upper left and lower right, next to the two large galaxies, some galaxies appear to be noticeably bent due to gravity.

Maybe they're doing a dance where they're one, couldn't they? Could be.