NGC 4567 and NGC 4568 (nicknamed the Butterfly Galaxies[4] or Siamese Twins[NB 1][5]) are a set of unbarred spiral galaxies about 60 million light-years away[1] in the constellation Virgo.

These galaxies are in the process of colliding and merging with each other, as studies of their distributions of neutral and molecular hydrogen show, with the highest star-formation activity in the part where they overlap.

However, the system is still in an early phase of interaction.

On August 5, 2020, NASA announced that they would not use that nickname in an effort to avoid systemic discrimination in their terminology.

This spiral galaxy article is a stub.