Astronomers watching the sky recently got a big surprise. They discovered a big galaxy in an undiscovered region of our galaxy. It appeared seemingly out of nowhere.
So, how did the galaxy, called Crater 2, achieve this feat, much like a deer leaping from intergalactic bushes to peer down our collective headlights? While Crater 2's appearance may appear sudden, he has been present the entire time. We simply ignored it.
However, now that we know it exists, astronomers have discovered a few more humiliating qualities. To begin, we cannot attribute the galaxy's relative obscurity to its size. Crater 2 is so massive that it has already been designated as the fourth largest galaxy in our galaxy's orbit. We can't blame its distance either. The orbit of Crater 2 around the Milky Way places it immediately overhead.
With that stated, how did we manage to miss it? Researchers at the University of Cambridge have an answer for us in a recent publication published in Monthly Notices of the Royal Astronomical Society. Despite its size and proximity, Crater 2 is likewise a rather dark galaxy. Indeed, it is one of the faintest galaxies ever discovered. This, together with several considerably brighter neighbours, allowed the galaxy dubbed “the feeble giant” to remain undetected until today.
However, now that we've seen Crater 2, the discovery raises questions about what more might exist. Researchers are already talking about starting a search for such massive, black galaxies in our neighbourhood. It serves as a fantastic reminder that there is still a lot about space that we don't comprehend.
Reference(s): Peer-Reviewed Research Paper