20461 Dioretsa - en.LinkFang.org

20461 Dioretsa

20461 Dioretsa
Discovery [1]
Discovered byLINEAR
Discovery siteLincoln Lab ETS
Discovery date8 June 1999
(20461) Dioretsa
Named after
(spelled backwards)
1999 LD31
centaur[3] · damocloid[4]
unusual[5] · distant[1]
Orbital characteristics[3]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 2
Observation arc2.54 yr (927 d)
Aphelion45.404 AU
Perihelion2.4021 AU
23.903 AU
116.87 yr (42,686 d)
0° 0m 30.24s / day
Jupiter MOID0.1907 AU
Physical characteristics
Mean diameter

20461 Dioretsa /d.əˈrɛtsə/ is a centaur and damocloid on a retrograde, cometary-like orbit from the outer Solar System. It was discovered on 8 June 1999, by members of the LINEAR team at the Lincoln Laboratory Experimental Test Site near Socorro, New Mexico, United States.[1] The highly eccentric unusual object measures approximately 14 kilometers (8.7 miles) in diameter.[4][6] It was named Dioretsa, the word "asteroid" spelled backwards.[1]


Classification and orbit

Dioretsa is a member of the damocloids,[4] with a retrograde orbit and a negative TJupiter of −1.547. It is also a centaur, as its orbit has a semi-major axis in between that of Jupiter (5.5 AU) Neptune (30.1 AU).[3] The Minor Planet Center lists it as a critical object and (other) unusual minor planet due to an orbital eccentricity of more than 0.5.[5]

It orbits the Sun at a distance of 2.4–45.4 AU once every 116 years and 10 months (42,686 days; semi-major axis of 23.9 AU). Its orbit has an eccentricity of 0.90 and an inclination of 160° with respect to the ecliptic.[3] Its observation arc begins 12 months prior to its official discovery observation, with a precovery taken by Spacewatch at Steward Observatory in June 1998.[1] Currently, its orbit still has an uncertainty of 2.[3]

Retrograde orbit

An inclination of greater than 90° means that a body moves in a retrograde orbit. 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.[citation needed]


The minor planet's name "Dioretsa" is the word "asteroid" spelled backwards, and is the first numbered of currently 99 known minor planets with a retrograde motion in the Solar System.[2] The approved naming citation was published by the Minor Planet Center on 1 May 2003 (M.P.C. 48396).[7]

Physical characteristics

According to observations made with the 10-meter Keck Telescope, Dioretsa measures 14 kilometers in diameter and its surface has a low albedo of 0.03.[6] It has an absolute magnitude of 13.8.[3] As of 2018, Dioretsa's spectral type as well as its rotation period and shape remain unknown.[3][8]


  1. ^ a b c d e f "20461 Dioretsa (1999 LD31)" . Minor Planet Center. Retrieved 20 November 2018.
  2. ^ a b Schmadel, Lutz D. (2006). "(20461) Dioretsa [24.4, 0.90, 160.2]". Dictionary of Minor Planet Names – (20461) Dioretsa, Addendum to Fifth Edition: 2003–2005. Springer Berlin Heidelberg. p. 152. doi:10.1007/978-3-540-34361-5_1728 . ISBN 978-3-540-34360-8.
  3. ^ a b c d e f g h "JPL Small-Body Database Browser: 20461 Dioretsa (1999 LD31)" (2000-12-29 last obs.). Jet Propulsion Laboratory. Retrieved 20 November 2018.
  4. ^ a b c d e Johnston, Wm. Robert (7 October 2018). "List of Known Trans-Neptunian Objects" . Johnston's Archive. Retrieved 20 January 2018.
  5. ^ a b "List Of Other Unusual Objects" . Minor Planet Center. 14 November 2018. Retrieved 20 November 2018.
  6. ^ a b c d Harris, Alan W.; Delbó, Marco; Binzel, Richard P.; Davies, John K.; Roberts, Julie; Tholen, David J.; et al. (October 2001). "Visible to Thermal-Infrared Spectrophotometry of a Possible Inactive Cometary Nucleus" . Icarus. 153 (2): 332–337. Bibcode:2001Icar..153..332H . doi:10.1006/icar.2001.6687 . Retrieved 4 April 2016.
  7. ^ "MPC/MPO/MPS Archive" . Minor Planet Center. Retrieved 20 November 2018.
  8. ^ "LCDB Data for (20461) Dioretsa" . Asteroid Lightcurve Database (LCDB). Retrieved 27 June 2017.

External links

Categories: Minor planet object articles (numbered) | Centaurs (minor planets) | Damocloids | Unusual minor planets | Discoveries by LINEAR | Named minor planets | Astronomical objects discovered in 1999

Information as of: 15.07.2020 11:12:28 CEST

Source: Wikipedia (Authors [History])    License : CC-by-sa-3.0

Changes: All pictures and most design elements which are related to those, were removed. Some Icons were replaced by FontAwesome-Icons. Some templates were removed (like “article needs expansion) or assigned (like “hatnotes”). CSS classes were either removed or harmonized.
Wikipedia specific links which do not lead to an article or category (like “Redlinks”, “links to the edit page”, “links to portals”) were removed. Every external link has an additional FontAwesome-Icon. Beside some small changes of design, media-container, maps, navigation-boxes, spoken versions and Geo-microformats were removed.

Please note: Because the given content is automatically taken from Wikipedia at the given point of time, a manual verification was and is not possible. Therefore LinkFang.org does not guarantee the accuracy and actuality of the acquired content. If there is an Information which is wrong at the moment or has an inaccurate display please feel free to contact us: email.
See also: Legal Notice & Privacy policy.