is a trans-Neptunian object and the tenth-most-distant known object in the Solar System . Considered a

detached object Detached objects are a dynamical class of minor planets in the outer reaches of the Solar System and belong to the broader family of trans-Neptunian objects (TNOs). These objects have orbits whose points of closest approach to the Sun (perihelion ...

, it orbits the Sun in a highly eccentric orbit every 3,305 years at an average distance of 222 astronomical units (AU).

Description

Mike Brown's website lists it as a possible dwarf planet with a diameter of based on an assumed albedo of 0.04 . The albedo is expected to be low because the object has a blue (neutral) color. However, if the albedo is higher, the object could easily be half that size. and Sedna differ from scattered-disc objects in that they are not within the gravitational influence of the planet

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 ...

even at their perihelion distances (closest approaches to the Sun). It is something of a mystery as to how these objects came to be in their current, far-flung orbits. Several hypotheses have been put forward: * They were pulled from their original positions by a passing star. * They were pulled from their original positions by a very distant, and as-yet-undiscovered (albeit unlikely), giant planet. * They were pulled from their original positions by an undiscovered companion star orbiting the Sun such as

Nemesis In ancient Greek religion, Nemesis, also called Rhamnousia or Rhamnusia ( grc, Ῥαμνουσία, Rhamnousía, the goddess of Rhamnous), was the goddess who personifies retribution, a central concept in the Greek world view. Etymology The n ...

. * They were captured from another

planetary system A planetary system is a set of gravitationally In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interacti ...

during a close encounter early in the Sun's history. According to Kenyon and Bromley, there is a 15% probability that a star like the Sun had an early close encounter and a 1% probability that outer planetary exchanges would have happened. is estimated to be 2–3 times more likely to be a captured planetary object than Sedna. Planet_nine_15_etno2_2017

is the first object discovered in the Solar System to have a

semi-major axis In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the long ...

exceeding 150 AU, a perihelion beyond Neptune, and an argument of perihelion of . It is one of eleven objects known with a semi-major axis greater than 100 AU and perihelion beyond 42 AU. It may be influenced by

Planet Nine Planet Nine is a hypothetical planet in the outer region of the Solar System. Its gravitational effects could explain the peculiar clustering of orbits for a group of extreme trans-Neptunian objects (ETNOs), bodies beyond Neptune that orbit t ...

References

External links

Orbit Determination of

Spacecraft escaping the Solar System
(Heavens-Above) * World Book

* * {{DEFAULTSORT:2000 CR105 148209 148209 Discoveries by Marc Buie 20000206

Description

See also

References

External links