They have to have something like this to implement the Kepler systems they have (there's too many to do manually I suspect), but I have no idea how to access this or if us users can. I might be wrong though, the devs might just have spent a ton of time putting the Kepler systems they have in, or maybe there just isn't that many, I don't know, but I'd like to be able to use this sort of thing too or at least be able to export and import them with a format that we can design. Maybe a "User Star System" tab in the add menu?
Though you might want to take a look at the save file of a already built star system, maybe you can textually edit that, I dont know.