Eight likeliest dwarf planets and dates of discovery A dwarf planet is a small planetary-mass object that is in direct orbit around the Sun, massive enough...

Eris (minor-planet designation: 136199 Eris) is the most massive and second-largest known dwarf planet in the Solar System. It is a trans-Neptunian object...

The number of dwarf planets in the Solar System is unknown. Estimates have run as high as 200 in the Kuiper belt and over 10,000 in the region beyond...

Ceres (minor-planet designation: 1 Ceres) is a dwarf planet in the middle main asteroid belt between the orbits of Mars and Jupiter. It was the first known...

Pluto, and Eris in the category of dwarf planet, although many planetary scientists have continued to apply the term planet more broadly. Further advances...

Brown dwarfs are substellar objects that have more mass than the biggest gas giant planets, but less than the least massive main-sequence stars. Their...

Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of bodies beyond the orbit of Neptune. It is the ninth-largest...

parent planet as I (Ariel), II (Umbriel), III (Titania), and IV (Oberon), and this finally stuck. At the time of Neptune's discovery, dwarf planet Ceres...

consensus among astronomers that the Solar System has at least eight dwarf planets: Ceres, Pluto, Haumea, Quaoar, Makemake, Gonggong, Eris, and Sedna....

A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's...