Betelgeuse IV was a Federation member planet in the Betelgeuse star system. It was one of three class M planets in the system and at one time had a Betelgeusian population.
Betelgeusians considered it their homeworld, and gave it the indigenous name of Hav'a'halar. (Decipher RPG module: Aliens)
History[]
As the star Betelgeuse was entering a later stage of life, heading toward a supernova that would endanger worlds for parsecs around it, the Betelgeusians migrated out of the region, living on space stations and starships. (TOS novel: Ex Machina)