Dagda's Wheel

From Tardis Wiki, the free Doctor Who reference

Dagda's Wheel was the name the inhabitants of Tír na n-Óg gave to their sun. It was an artificial sun installed by Goibhnie in addition to a cooler native sun, Arawn's Wheel. It went out when Goibhnie's experiment was finished, but the Seventh Doctor transmated protoplasm to it to fuel Arawn's Wheel for another 2,000 years. (PROSE: Cat's Cradle: Witch Mark)