Planetary-mass object

any celestial object massive enough to achieve hydrostatic equilibrium, but not enough to sustain core fusion like a star

Planetary-mass object, planetary body or planemo is the name used to define objects having mass to be round, but not enough to host nuclear fusion like stars. They orbit around another astronomical object. It includes dwarf planets, moons and other obiects.

Star, brown dwarf and planemo size comparison

Origin

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The term was created by the IAU to define object whether they are planets or not. According to the geophysical definition, a planet is an astronomical object that has mass to become round, but insufficient to host nuclear fusion like stars.

In the solar system

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If we apply this to our Solar System, they will be planetary bodies:

    1. Mercury
    2. Venus
    3. Earth
    4. Mars
    5. Vesta
    6. Pallas
    7. Ceres
    8. Hygiea
    9. Jupiter
    1. Saturn
    2. Uranus
    1. Neptune
    2. 2011 KT19
    3. Orcus
    4. (55638) 2002 VE95
    5. Lempo
    6. Pluto
    7. Huya
    8. Ixion
    9. Salacia
    10. Praamzius
    11. Varuna
    12. (55636) 2002 TX300
    13. Haumea
    14. Quaoar
    1. Sila-Nunam
    2. Deucalion
    3. Albion
    4. Altjira
    5. Makemake
    6. (55637) 2002 UX25
    7. (55565) 2002 AW197
    8. (307261) 2002 MS4
    9. Gonggong
    10. Eris
    11. Sedna