The Kether-Tiphereth system was a binary star system which was not home to any humanoids, but was home to the Yesodi (PROSE: After Life) and later the Yesodites. The Eighth Doctor considered it to be one of the most spectacular solar systems in its galaxy. Yesod and Malkuth were both in this system. (PROSE: The Long Midwinter)
At least one of its stars, Kether, was visible from Murigen. (PROSE: Predating the Predators)
Behind the scenes[]
The stars and planets of this fictional star system take their names from sephirot of the Kabbalistic Tree of Life: Kether, Tiphereth, Malkuth, and Yesod.