<P> The International Astronomical Union (IAU) currently recognizes five dwarf planets: Ceres; Pluto; Haumea; Makemake; and Eris . Brown criticizes this official recognition: "A reasonable person might think that this means that there are five known objects in the solar system which fit the IAU definition of dwarf planet, but this reasonable person would be nowhere close to correct ." </P> <P> Another hundred or so known objects in the Solar System are suspected to be dwarf planets . Estimates are that up to 200 dwarf planets will be identified when the entire region known as the Kuiper belt is explored, and that the number may exceed 10,000 when objects scattered outside the Kuiper belt are considered . Individual astronomers recognize several of these, and in August 2011 Mike Brown published a list of 390 candidate objects, ranging from "nearly certain" to "possible" dwarf planets . Brown currently identifies ten known trans - Neptunian objects--the four accepted by the IAU plus 2007 OR, Quaoar, Sedna, Orcus, (307261) 2002 MS 4 and Salacia--as "virtually certain", with another twenty highly likely . Stern states that there are more than a dozen known dwarf planets . </P> <P> Only two of these bodies, Ceres and Pluto, have been observed in enough detail to demonstrate that they actually fit the IAU's definition . The IAU accepted Eris as a dwarf planet because it is more massive than Pluto . They subsequently decided that unnamed trans - Neptunian objects with an absolute magnitude brighter than + 1 (and hence a diameter of ≥ 838 km assuming a geometric albedo of ≤ 1) are to be named under the assumption that they are dwarf planets . </P> <P> The classification of bodies in other planetary systems with the characteristics of dwarf planets has not been addressed . </P>

How does a planet become a dwarf planet