This ghost galaxy is 99% dark matter with only four star clusters

The low-surface-brightness galaxy CDG-2, within the dashed red circle, is dominated by dark matter and contains only a sparse scattering of stars. (NASA)

CDG-2 (short for Candidate Dark Galaxy-2) has so few stars that it’s basically invisible. The only reason anyone noticed it at all is that four globular clusters were hanging out together about 300 mill…