Invisible Galaxies: 70 Candidates for Dark Worlds
The FAST radio telescope in China is a giant dish half a kilometer in diameter, nestled in a natural sinkhole among mountains.
A vacuum cleaner at the heart of a dwarf: how a black hole gathers gas from dying stars
At the center of an ultra-compact dwarf galaxy, a very dense stellar system spanning tens of light-years, there is a vacuum cleaner at work. But instead of dust, it sucks in gas shed by dying stars. This gas does not fly off in all directions; instead, it spirals into a funnel, a rotating disk that gradually settles onto the black hole.