I found some mistakes in 'Halo.sc', which I have corrected. Even missing is a sun for the 'Coelest' system. I created two scripts, very rudimentary, because I'm not a Halo fan and have no idea where this star is, or how it should look like.
The 'CoelestSystem.sc' goes in configs\stars, the 'CoelestSun.sc' in configs\planets. They also have to be added to the universe.cfg.