冥めい王おう星せい族ぞく

Meanings

1

noun

plutino

astronomy

Astronomical term for a trans-Neptunian object in 2:3 orbital resonance with Neptune, like Pluto. Used in scientific contexts.

tribe, family

冥めい王おう星せい
冥王星 is Pluto itself, while 冥王星族 refers to the class of objects sharing Pluto's orbital resonance.
太たい陽よう系けい外がい縁えん天てん体たい
太陽系外縁天体 is a broader term for trans-Neptunian objects; 冥王星族 is a specific subgroup.

Compound of 冥王星 (Pluto) + 族 (tribe, family), literally 'Pluto family', referring to objects sharing Pluto's orbital characteristics.