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, "Metulla Orionis" in the novel The Quantum Archangel and "Metulla Orionsis" in An Ood Thing to Say.