Discovered by LINEAR MPC designation 20461 Dioretsa Orbital period 116 years Aphelion 45 m Discovery site Experimental Test Site | Discovery date 8 June 1999 Alternative names 1999 LD31 Discovered 8 June 1999 Orbits Sun | |
Pronunciation /daɪ.əˈrɛtsə/
dy-ə-RET-sə Named after Asteroid
(spelled backwards) Discoverer Lincoln Near-Earth Asteroid Research Similar Sun, Solar System, 5335 Damocles, 52872 Okyrhoe, 8405 Asbolus | ||
20461 Dioretsa (dy-ə-RET-sə), provisional designation 1999 LD31, is a distant minor planet classified as centaur, with a highly eccentric and retrograde orbit, approximately 14 kilometers in diameter. It was discovered 8 June 1999, by members of the Lincoln Near-Earth Asteroid Research (LINEAR) team at the U.S. Lincoln Laboratory Experimental Test Site, Socorro, New Mexico.
The centaur orbits the Sun at a distance of 2.4–45.3 AU once every 116 years and 5 months (42,535 days). Its orbit has an eccentricity of 0.90 and an inclination of 160° with respect to the ecliptic. An inclination greater than 90° means that a body moves in a retrograde orbit. Currently, its orbit has an uncertainty parameter value of 2. The first precovery was taken at Steward Observatory (Kitt Peak–Spacewatch) in 1998, extending Dioretsa's observation arc by 1 year prior to its discovery. Dioretsa's orbit is otherwise similar to that of a comet. This has led to speculation that Dioretsa was originally an object from the Oort cloud.
The minor planet's name "Dioretsa" is the word "asteroid" spelled backwards, and is the first numbered of currently more than 20 known minor planets with a retrograde motion in the Solar System. Naming citation was published on 1 May 2003 (M.P.C. 48396).