© ESO
The newly spotted dwarf galaxy, which has been named Crater 2, sits around 400,000 light-years away, and has already earned the title of the fourth largest known galaxy circling our own.
So how does a galaxy that big stay hidden for so long? Crater 2 has always been there, quietly circling our own giant galaxy. But its stars are so diffuse that it's incredibly dark, and it's been masked up until now by its brighter neighbours. In fact, it's one of the dimmest galleries every detected in the Universe.
"This is indeed a very rare discovery," lead researcher Vasily Belokurov from the University of Cambridge in the UK
told The Huffington Post. "A galaxy like Crater 2 is a sort of invisible object."
As far as we know, the Milky Way is orbited by 49 other galaxies, but this research suggests that perhaps there are other dark galaxies, inside our own cosmic neighbourhood, that have remained hidden because of their diffuse, ghostly appearance.
Crater 2 was first detected in January, when astronomers used a computer algorithm to study images taken by the Very Large Telescope in Chile, and then pinpoint regions where there might be unusual clustering of stars - one of those clusters turned out to be Crater 2.
Comment: Slowly and gently increasing public awareness of brown dwarf stars may be part of a wider scientific agenda of disclosure: