The new group, designated CGG-z4, hosts two optically dark star-forming galaxies. The finding was detailed in a research paper published Jan. 9 on the pre-print server arXiv. Galaxy groups are the ...

it became clear that the Milky Way was only one star system (or galaxy) among myriad others. This was the birth of our modern universe of galaxies, so poetically celebrated in Seeing in the Dark.

Dark stars can be incredibly huge, stretching for thousands of light-years, while still having relatively low density. This would match observations of galaxy cores, which makes this an intriguing ...