A member of the Kuiper Belt with an average distance from the Sun of around 39.5 AU, the same as that of Pluto, hence the name Plutino (‘little Pluto’). An object at such a distance orbits the Sun twice in the time that Neptune takes to complete three orbits, and so is in a 3:2 resonant orbit with Neptune. About 25 % of the known Kuiper Belt objects are Plutinos, although this percentage will probably fall as more distant members of the Kuiper Belt are discovered. The first object confirmed to be in such an orbit was 1993 SC, subsequently numbered (15789), which has a semimajor axis of 39.76 AU, perihelion 32.26 AU, aphelion 47.26 AU, inclination 5°.1 , and period 250.7 years.
Subjects: Astronomy and Astrophysics.