Word.ws English Dictionary

planemo

Syllables: pla·ne·mo/ˈplæ.nə.moʊ/

planemo noun: an astronomical object with enough mass to achieve hydrostatic equilibrium, but not enough to initiate core fusion at any time in its existence. That is, it is rounded in shape and is smaller than a star. Planemos include planets, dwarf planets, and the larger moons of the Solar System (satellite planets), but also sub-brown dwarfs and rogue planets between the stars.

Noun

planemo (plural planemos)

  1. an astronomical object with enough mass to achieve hydrostatic equilibrium, but not enough to initiate core fusion at any time in its existence. That is, it is rounded in shape and is smaller than a star. Planemos include planets, dwarf planets, and the larger moons of the Solar System (satellite planets), but also sub-brown dwarfs and rogue planets between the stars.
    • Other groups have also recently identified young, isolated planemos; understanding how such isolated, ultra-low masses form presents a challenge.2003 December 1, Jacques Lépine, Jane Gregorio-Hetem, Open Issues in Local Star Formation, page 266

Forms of planemo

pluralplanemos

Origin of planemo

Contraction of planetary-mass object. Coined by Gibor Basri, Professor of Astronomy at the University of California, Berkeley, (UCB) at the 2003 IAU conference.

Questions about planemo

What does planemo mean?
Planemo means an astronomical object with enough mass to achieve hydrostatic equilibrium, but not enough to initiate core fusion at any time in its existence. That is, it is rounded in shape and is smaller than a star. Planemos include planets, dwarf planets, and the larger moons of the Solar System (satellite planets), but also sub-brown dwarfs and rogue planets between the stars.
What part of speech is planemo?
Planemo is a noun.
How do you pronounce planemo?
Planemo is pronounced /ˈplæ.nə.moʊ/.
What is the plural of planemo?
The plural of planemo is planemos.

Words near planemo in the dictionary

  1. planelike
  2. planeload
  3. planeloads
  4. planemaker
  5. planemakers
  6. planemo
  7. planemos
  8. planeness
  9. planenesses
  10. planer
  11. planer tree

Source and license

Adapted from Wiktionary: planemo (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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