Discovery and designation
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Discovered by | Lincoln Laboratory Near-Earth Asteroid Research Team at Socorro[1] |
Discovery date | 8 June 1999 |
Designations
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MPC designation | 20461 |
Alternate name(s) | 1999 LD31 |
Minor planet category |
centaur[1], damocloid |
Epoch 2455800.5 (2011 Aug 27.0) | |
Aphelion | 45.296 AU |
Perihelion | 2.363606 AU |
Semi-major axis | 23.8297 AU |
Eccentricity | 0.900813 |
Orbital period | 42489 days (116.329 y) |
Mean anomaly | 36.425° |
Inclination | 160.41900° (retrograde) |
Longitude of ascending node | 297.41955° |
Argument of perihelion | 102.5329° |
Absolute magnitude (H) | 13.8[1] |
Dioretsa (1999 LD31) ( /daɪ.əˈrɛtsə/ dy-ə-ret-sə) is a centaur[1] discovered in 1999 notable for its unusual orbit, which is highly eccentric and retrograde. Its name is the word 'asteroid' spelled backwards to reflect this fact. It is one of twenty or so known minor planets in the Solar System that have a retrograde orbit—see the List of notable asteroids.
Dioretsa's orbit is otherwise similar to a comet's; it has a perihelion of 2.4 AU and an aphelion of 45.3 AU. This has led to speculation that Dioretsa was originally an object from the Oort cloud.
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