Dwarf planet a draft resolution for the IAU definition of planet, both Pluto and Charon would have been considered dwarf planets in a binary system, given that they both satisfied the mass and shape requirements for dwarf planets and revolved around a common center of mass located between the two bodies (rather than within one of the bodies). The IAU currently states that Charon is not considered to be a dwarf planet and is just a satellite of Pluto, although the idea that Charon might qualify to be a dwarf planet in its own right may be considered at a later date.
Gas dwarf extrasolar planet that might be a gas dwarf is Kepler-138d, which is less massive than Earth but has a 60% larger volume and therefore has a density (2.1(+2.2/-1.2) grams per cubic centimetre) that indicates either a substantial water content or possibly a thick gas envelope. A low-mass gas planet can still have a radius resembling that of a gas giant if it has the right temperature. Gas dwarf A gas dwarf is a gas planet with a rocky core that has accumulated a thick envelope of hydrogen, helium, and other volatiles, having as result a total radius between 1.7 and