Betelgeuse V

Betelgeuse V, (PROSE: Lords of the Storm) often called just Betelgeuse, was a planet mentioned several times by the Fourth Doctor.

Professor Chronotis owned a travel guide entitled Alternative Betelgeuse. (PROSE: Shada)

Geography
Betelgeuse V used to have a moon, though it was later destroyed. (PROSE: Lords of the Storm) The Third Doctor remembered seeing a double sunrise on Betelgeuse. (PROSE: The Loneliness of the Long-Distance Time Traveller)

History
In 4500, when Davros was revived and had demanded to know what had happened while he was in suspended animation, the Doctor told him that Betelgeuse had placed second in the Galactic Olympic Games, behind Arcturus (TV: Destiny of the Daleks) or Earth. (PROSE: Doctor Who and the Destiny of the Daleks)

Undated events
The Seventh Doctor mentioned a visit to Betelgeuse while at the Grand Betelgeuse Hotel. (AUDIO: The Grand Betelgeuse Hotel)

Behind the scenes

 * In the real world, the star Betelgeuse is not known to have any inhabitable planets in its orbits, but the name "Betelgeuse V" implies that the inhabited "planet Betelgeuse" is the fifth planet revolving around Betelgeuse.
 * was a planet in script editor Douglas Adams' The Hitchhiker's Guide to the Galaxy series, where it is mentioned as the homeworld of Ford Prefect and Zaphod Beeblebrox.