In planetary classification, a class B gas giant is a type of planet. As the name describes, the planet is generally composed of a tenuous gas concentration, with or without a more solid subsurface or core. In particular among gas giant planets, the class B worlds of this type are not radiant of heat and energy, differing in this respect from the class A gas giant. Neptune is an example of a class B non-radiant gas body. (ST references: Star Trek Maps, The Worlds of the Federation)