10370 Hylonome is a Small Solar System Body

Small solar system body

A small Solar System body is an object in the Solar System that is neither a planet nor a dwarf planet, nor a satellite of a planet or dwarf planet:...

 orbiting in the outer Solar System. It belongs to the class of icy objects that are known as centaurs, with an orbit that crosses the orbit of Neptune

Neptune

Neptune is the eighth and farthest planet from the Sun in the Solar System. Named for the Roman god of the sea, it is the fourth-largest planet by diameter and the third largest by mass. Neptune is 17 times the mass of Earth and is slightly more massive than its near-twin Uranus, which is 15 times...

 and grazes that of Uranus

Uranus

Uranus is the seventh planet from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System. It is named after the ancient Greek deity of the sky Uranus , the father of Cronus and grandfather of Zeus...

. It was discovered on February 27, 1995.

10370 Hylonome was named for Hylonome

Hylonome

Hylonome was a female centaur in Greek mythology. She was present at the battle against the Lapiths, where she lost her husband, the centaur Cyllarus, whom she loved very much. Heartbroken, she then took her own life to join him....

, a female centaur

Centaur

In Greek mythology, a centaur or hippocentaur is a member of a composite race of creatures, part human and part horse...

 in Greek mythology

Greek mythology

Greek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...

.

Observations with the infrared Spitzer Space Telescope

Spitzer Space Telescope

The Spitzer Space Telescope , formerly the Space Infrared Telescope Facility is an infrared space observatory launched in 2003...

 show a diameter of 10370 to be 70 km (43.5 mi) plus or minus 20 km (50 to 90 km in diameter), or a 35 km radius.

Orbit

The orbits of centaurs are unstable due to perturbations

Perturbation (astronomy)

Perturbation is a term used in astronomy in connection with descriptions of the complex motion of a massive body which is subject to appreciable gravitational effects from more than one other massive body....

 by the giant planets. Currently Uranus controls Hylonome's perihelion

Apsis

An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...

 and Neptune its aphelion. It is estimated to have a relatively long orbital half-life of about 6.37 Myr

Myr

The symbol myr was formerly used in English-language geology, and remains as the standard usage in astronomy, as a unit of one million years.It is an abbreviation for 'million years' and lower case is used in geology, while upper case is used in astronomy....

. In the year 3478, Hylonome will pass within ~85Gm of Uranus and its semi-major axis will be reduced to 23.5AU.

External links

• Hylonome as seen around 08 Sept 2009 by the new Hubble WFC3
  Wide Field Camera 3
  The Wide Field Camera 3 is the Hubble Space Telescope's last and most technologically advanced instrument to take images in the visible spectrum...
  
  .
• List of Centaurs and SDOs.