A Galaxy with No Stars

Mark Peplow in Nature:

Dark_1A galaxy that is made almost entirely of dark matter has been discovered. It’s the first galaxy found to have no stars at all, but it fits well with predictions made by astrophysicists about where the Universe’s missing mass should be.

“We’ve thrown as many tests at it as we can, and it looks like a dark galaxy,” says Robert Minchin from Cardiff University, UK, one of an international team of astronomers that made the find.

Dark matter betrays its presence by its gravitational pull: without dark matter to hold them together, rapidly rotating galaxies would simply fly apart. Scientists estimate that dark matter must be five times more abundant than normal matter in our Universe. It is likely to be made of relatively large subatomic particles that rarely interact with their surroundings, although these particles have never been identified.

More here.