We announce the discovery of a new Galactic companion found in data from the ESO VST ATLAS survey , and followed up with deep imaging on the 4m William Herschel Telescope .
The satellite is located in the constellation of Crater ( the Cup ) at a distance of \sim 170 kpc .
Its half-light radius is r _ { h } = 30 pc and its luminosity is M _ { V } = -5.5 .
The bulk of its stellar population is old and metal-poor .
We would probably have classified the newly discovered satellite as an extended globular cluster were it not for the presence of a handful of Blue Loop stars and a sparsely populated Red Clump .
The existence of the core helium burning population implies that star-formation occurred in Crater perhaps as recently as 400 Myr ago .
No globular cluster has ever accomplished the feat of prolonging its star-formation by several Gyrs .
Therefore , if our hypothesis that the blue bright stars in Crater are Blue Loop giants is correct , the new satellite should be classified as a dwarf galaxy with unusual properties .
Note that only ten degrees to the North of Crater , two ultra-faint galaxies Leo IV and V orbit the Galaxy at approximately the same distance .
This hints that all three satellites may once have been closely associated before falling together into the Milky Way halo .