Umayma

Name used to designate the planet by Nasheen, Chenja, and Tirhan.(org. Arabic. "Young, little mother.") Umayma is located in a remote region of an unknown galaxy. Thought to be located on the far arm of a very, very old spiral galaxy, it is so far from other systems that few stars are visible at night. Historians and astrologers note that Umayma and its two moons appear to be the only planets in their solar system.

From God's War:

Colonists had been barred from Umayma for a thousand years. Nyx hadn’t even seen a ship in a decade. Umayma sat at the edge of everything; most of the sky was dark at night. All she ever saw moving up there were dead satellites and broken star carriers from the beginning of the world.