海かい王おう星せい外がい天てん体たい

noun

trans-Neptunian object; TNO

Technical astronomy term for any minor planet or dwarf planet orbiting the Sun beyond Neptune. Often abbreviated as TNO in English.

• 冥めい王おう星せいは海かい王おう星せい外がい天てん体たいの一ひとつに分ぶん類るいされる。

  Pluto is classified as one of the trans-Neptunian objects.