(

provisional designation Provisional designation in astronomy is the naming convention applied to astronomical objects immediately following their discovery. The provisional designation is usually superseded by a permanent designation once a reliable orbit has been calcu ...

) is a

twotino In astronomy, a resonant trans-Neptunian object is a trans-Neptunian object (TNO) in mean-motion orbital resonance with Neptune. The orbital periods of the resonant objects are in a simple integer relations with the period of Neptune, e.g. 1:2, 2 ...

, that is, a planetoid in a 1:2 orbital resonance with

Neptune Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...

. It was discovered on November 16, 2002 at the

Palomar Observatory Palomar Observatory is an astronomical research observatory in San Diego County, California, United States, in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observat ...

. If its derived diameter is correct it would have a higher density than

Pluto Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the S ...

, which is unusual as it appears to be much smaller than the expected size at which a Kuiper belt object usually becomes solid. Knowing how many twotinos there are may reveal whether Neptune took roughly 1 million or 10 million years to migrate about 7 AU from its birth location.

Satellite

A natural satellite was reported to be orbiting (named S/2007 (119979) 1) on February 27, 2007. It is estimated to be from the primary, with an orbital period of days, an eccentricity of and an inclination of . Assuming similar albedos, it is a quarter the diameter of its primary, or around in diameter. file:2002WC19-orbit.png, Orbit of compared to Pluto and Neptune, alt=alt language file:TNO-2002WC19.gif, 1:2

libration In lunar astronomy, libration is the wagging or wavering of the Moon perceived by Earth-bound observers and caused by changes in their perspective. It permits an observer to see slightly different hemispheres of the surface at different tim ...

over 20,000 years – Neptune is held stationary (dot at 5 o'clock); orbit of Uranus in blue, alt=alt language

References

External links

* {{DEFAULTSORT:119979 Twotinos Discoveries by the Palomar Observatory Possible dwarf planets Binary trans-Neptunian objects 20021116