From Rise: The Vieneo Province

Ostlon was once a gas giant near the edge of the Yonmaran system. At some time in the distant past, Ostlon was destroyed, leaving in its orbit a huge debris field containing many exotic gas and particle forms, as well as two remaining moons. By laying in-line with the galactic plane, this outer debris field encapsulated the entire system, and was partially to blame for Yonmaran’s ability to evade sensors