NGC 3314

NGC 3314 consists of two spiral galaxies that appear to overlap in the constellation Hydra. British astronomer John Herschel first spotted the pair on 24 March 1835, but neither he nor later observers realized that what looked like a single galaxy was actually two separate galaxies lying along the same line of sight.

This unusual alignment lets astronomers study interstellar dust in the foreground galaxy, NGC 3314a, which is seen face-on. The dust shows up as dark blue patches against the light of the background galaxy, NGC 3314b. Despite their visual overlap, the two galaxies are not interacting—they are physically unrelated and too far apart to influence each other.

In March 2000, a bright green star-like object appeared in one of the galaxies’ arms. Astronomers suspected it might be a supernova, but the foreground galaxy’s filtering effects made a definite identification difficult. NGC 3314a’s spiral arms and abundant dust also heavily obscure the view of NGC 3314b.

A long dust tail extends from NGC 3314a, evidence of ram pressure stripping as the galaxy moves through the intracluster medium of its home cluster, the Hydra Cluster. Both galaxies are members of this cluster.