Mettula Orionsis

Mettula Orionsis was a star system that contained the planet Traken, the capitol of the Traken Union. At least three planets were seen to make up the system (one being Traken). (TV: The Keeper of Traken) Nyssa once described Mettula Orionsis as a constellation rather than a "star system". (PROSE: Divided Loyalties)

In 1981, a temporary wave of entropy swept across part of the universe, destroying Metulla Orionsis in the process. (TV: Logopolis)

Metulla Orionsis was visible in the night sky of Surobos. (COMIC: Shipwreck!)

The Eleventh Doctor said that the Ood could check the weather in the Metulla Orionsis system from their upgraded communicators. (COMIC: An Ood Thing to Say)

The Eighth Doctor recalled a saying in the Academy about how the beat of a butterfly's wings in Mettula Orionsis caused a time storm in the Mutter's Spiral. (AUDIO: Storm Warning)

Behind the scenes
This location was misspelled "Mettula Orionis" in the novel Divided Loyalties and "Metulla Orionis" in the novel The Quantum Archangel.