cis-Neptunian

English

Etymology

From cis- +‎ Neptunian; compare trans-Neptunian.

Adjective

cis-Neptunian (not comparable)

1. (astronomy) Relating to an astronomical body found within the orbit of Neptune.

   Coordinate term: trans-Neptunian

   • 2018, Michael Perryman, The Exoplanet Handbook, Cambridge University Press, →ISBN, page 684:

     Within the orbit of Neptune, cis-Neptunian bodies include the terrestrial and large gaseous planets, along with a variety of minor bodies: planetary moons, asteroids, and comets.

Usage notes

• The definition is somewhat vague: an object whose orbit is only partly inside that of Neptune might be neither cis-Neptunian nor trans-Neptunian – or perhaps both.
• The term is usually only applied to small Solar System bodies that directly orbit the Sun. It also may be stipulated that the orbit be beyond that of Jupiter.
• Neptunian trojans, which share Neptune's orbit, may or may not be included.