Enormous ‘Ghost’ Galaxy Spotted on Outskirts of Milky Way

Simons Foundation, November 2018

Astronomers have discovered a ghostlike galaxy that looms large on the fringes of the Milky Way. The newly discovered dwarf galaxy, dubbed Antlia 2, stretches roughly 19,000 light-years across. That makes it the vastest satellite galaxy of the Milky Way. Despite its enormous extent, though, Antlia 2 is incredibly faint and barren: It is by far the sparsest galaxy ever seen in the universe, its discoverers report in a paper posted November 13 at arXiv.org.