THE KIJIAN SYSTEM
There were six planets orbiting this orange dwarf star until the Urn arrived, pulling outermost Suul along with it. Now there are seven, three rocky inner planets, two gas giants, a frozen ocean world, and the Urn’s outer reliquary, aforementioned Suul. Most of these have their own moons and further details (mouse over any of them), and serve as story backdrop, astronomical detail, and even places to go if you’ve got the right stuff. The star itself itself is enclosed within a much larger nebular void, and is difficult to observe directly from neighboring systems. Right now, we're on Rym, third from the sun.
Of these worlds, only Vauz and Rym harbor life. Both were shaped by the Urn, each with its unique biomes and populations, and each overseen by voiceless, incomprehensible moon gods called 'Onai'. These giant sculptures exist on Rym's smaller moon, Zunat, and on Vauz's sole moon of Talionis. They alone know the Urn's purpose, though without their intermediary demigods, they're unapproachable. The rest of the system is devoid of life, with the possible exception of oceanic Naiyos, which drifted out of the star's habitable zone and froze solid.
Storytelling: It’s good to have some local astronomy, not just for the sake of an interesting night sky but so that the various cultures can have strange notions of what might be up there. They can be used for navigation, a source of legend, or even days of the week, though in this case they’re also good stand-ins for elemental planes of various sorts, and may be relevant in the case of visitors from other worlds.