Dark System

Dark Systems are solar systems within Hexamite space whose sun(s) have been converted into black holes by unknown means. Planets in orbit show clear evidence of once being lit by a sun, and other than an obvious absence of light appear undamaged.

As it is impossible for all but the largest of stars to collapse into black holes, especially without a system-wrecking supernova first taking place, the clear conclusion is this was done artificially by some unknown means (such as a hypothetical "Hexamite Starkiller"), perhaps during a civil war. More outlandish ideas include a theory the Hexamites were collapsing stars to save their energy and prevent it from being burned away in nuclear fusion, and that they had (or intended to develop) some means of getting the mass out of the black hole later on.

The resulting black holes are several kilometers across (asteroid-sized) at the most, identifiable at a distance only by their gravity and, in some cases, a feeble accretion disk of synthetic Hexamite compounds.

The Existential Risks Directorate takes a keen interest in these systems, and hopes no one digs up a working example of the weapon that created them.