betsymccall.net Lifelong Learning Astronomy Planets Ceres

When first discovered, Ceres, like Pluto, was also considered a planet, and then demoted to a mere "asteroid". Now it has the (official) graceless nomenclature of "dwarf planet". The largest object in the asteroid belt, a more general definition of planet would probably classify along with the terrestrial planets, but gravitational interference from Jupiter prevented the objects here from forming a larger body. I suppose "dwarf planet" is a step up from "asteroid". You will find that some sites have updated to the new nomenclature, while others have not.

Links:

Ceres (dwarf planet) - Wikipedia, the free encyclopedia

Dwarf Planet Ceres

Asteroid Ceres

Asteroid 1 Ceres - Explore the Cosmos | The Planetary Society

Asteroids

Ceres - The Discovery of Asteroid Ceres

Science: Ceres a Dwarf Planet

SPACE.com -- Largest Asteroid Might Contain More Fresh Water than Earth

Ceres upgraded to miniplanet

NASA ADS: Differentiation of the asteroid Ceres as revealed by its shape

NASA's Dawn Mission: To Explore 'Dwarf Planet' Ceres And Massive Asteroid Vesta