Coridan is a class M planet located in the 54 Orionis star system in the Beta Quadrant, and the capital world of the People's Republic of Coridan. One of the worlds that drew up the charter for the Coalition of Planets in 2155, Coridan withdrew from the alliance before it was signed. (ST reference: Star Charts, ENT episode: "Shadows of P'Jem", ENT novel: The Good That Men Do, TOS episode: "Journey to Babel")