NGC 3314 is a pair of overlapping spiral galaxies between 117-140 million light-years away in the constellation Hydra. This unique alignment gives astronomers the opportunity to measure the properties of interstellar dust in the face-on foreground galaxy (NGC3314a), which appear dark against the background galaxy (NGC 3314b). Unlike interacting galaxies, the two components of NGC3314 are physically unrelated.
While searching for overlapping galaxies in April 1999, two astronomers from the University of Alabama were the first to image the deep sky object in enough detail to tell that it was in fact two galaxies. In a March 2000 observation of the galaxies, a prominent green star-like object was seen in one of the arms. Astronomers theorized that it could have been a supernova, but the unique filtering properties of the foreground galaxy made it difficult to decide definitively.
Hubble data used: