| Discovery [1] | |
|---|---|
| Discovered by | LINEAR |
| Discovery site | Lincoln Lab ETS |
| Discovery date | 8 June 1999 |
| Designations | |
| (20461) Dioretsa | |
| Pronunciation | /daɪ.əˈrɛtsə/ |
Named after |
Asteroid
[2] (spelled backwards) |
| 1999 LD31 | |
|
centaur
[3] ·
damocloid
[4] unusual [5] · distant [1] | |
| Symbol |
.svg){kind=small} (astrological) |
| Orbital characteristics [3] | |
| Epoch 27 April 2019 ( JD 2458600.5) | |
| Uncertainty parameter 2 | |
| Observation arc | 2.54 yr (927 d) |
| Aphelion | 45.404 AU |
| Perihelion | 2.4021 AU |
| 23.903 AU | |
| Eccentricity | 0.8995 |
| 116.87 yr (42,686 d) | |
| 59.873 ° | |
| 0° 0m 30.24s / day | |
| Inclination | 160.43° |
| 297.77° | |
| 103.13° | |
| Jupiter MOID | 0.1907 AU |
| TJupiter | -1.5470 |
| Physical characteristics | |
Mean diameter | 14±3 km [4] [6] |
| 0.03±0.01 [4] [6] | |
| 13.8 [1] [3] | |
20461 Dioretsa /daɪ.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] As of 2021 [update], it was last observed in 2000 and 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]
Naming
The minor planet's name "Dioretsa" is the word " asteroid" spelled backwards, and is the first numbered of currently 136 known (see Data Base Search of the Minor Planet Center) 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]
References
- ^ a b c d e f "20461 Dioretsa (1999 LD31)". Minor Planet Center. Retrieved 20 November 2018.
- ^ 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.
- ^ 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.
- ^ a b c d e Johnston, Wm. Robert (7 October 2018). "List of Known Trans-Neptunian Objects". Johnston's Archive. Retrieved 20 January 2018.
- ^ a b "List Of Other Unusual Objects". Minor Planet Center. 14 November 2018. Retrieved 20 November 2018.
- ^ 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.
- ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 20 November 2018.
- ^ "LCDB Data for (20461) Dioretsa". Asteroid Lightcurve Database (LCDB). Retrieved 27 June 2017.
External links
- 20461 Dioretsa, Small Bodies Data Ferret
- Asteroid Lightcurve Database (LCDB), query form ( info Archived 16 December 2017 at the Wayback Machine)
- Dictionary of Minor Planet Names, Google books
- Discovery Circumstances: Numbered Minor Planets (20001)-(25000) – Minor Planet Center
- 20461 Dioretsa at AstDyS-2, Asteroids—Dynamic Site
- 20461 Dioretsa at the JPL Small-Body Database
| Discovery [1] | |
|---|---|
| Discovered by | LINEAR |
| Discovery site | Lincoln Lab ETS |
| Discovery date | 8 June 1999 |
| Designations | |
| (20461) Dioretsa | |
| Pronunciation | /daɪ.əˈrɛtsə/ |
Named after |
Asteroid
[2] (spelled backwards) |
| 1999 LD31 | |
|
centaur
[3] ·
damocloid
[4] unusual [5] · distant [1] | |
| Symbol |
(astrological) |
| Orbital characteristics [3] | |
| Epoch 27 April 2019 ( JD 2458600.5) | |
| Uncertainty parameter 2 | |
| Observation arc | 2.54 yr (927 d) |
| Aphelion | 45.404 AU |
| Perihelion | 2.4021 AU |
| 23.903 AU | |
| Eccentricity | 0.8995 |
| 116.87 yr (42,686 d) | |
| 59.873 ° | |
| 0° 0m 30.24s / day | |
| Inclination | 160.43° |
| 297.77° | |
| 103.13° | |
| Jupiter MOID | 0.1907 AU |
| TJupiter | -1.5470 |
| Physical characteristics | |
Mean diameter | 14±3 km [4] [6] |
| 0.03±0.01 [4] [6] | |
| 13.8 [1] [3] | |
20461 Dioretsa /daɪ.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] As of 2021 [update], it was last observed in 2000 and 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]
Naming
The minor planet's name "Dioretsa" is the word " asteroid" spelled backwards, and is the first numbered of currently 136 known (see Data Base Search of the Minor Planet Center) 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]
References
- ^ a b c d e f "20461 Dioretsa (1999 LD31)". Minor Planet Center. Retrieved 20 November 2018.
- ^ 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.
- ^ 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.
- ^ a b c d e Johnston, Wm. Robert (7 October 2018). "List of Known Trans-Neptunian Objects". Johnston's Archive. Retrieved 20 January 2018.
- ^ a b "List Of Other Unusual Objects". Minor Planet Center. 14 November 2018. Retrieved 20 November 2018.
- ^ 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.
- ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 20 November 2018.
- ^ "LCDB Data for (20461) Dioretsa". Asteroid Lightcurve Database (LCDB). Retrieved 27 June 2017.
External links
- 20461 Dioretsa, Small Bodies Data Ferret
- Asteroid Lightcurve Database (LCDB), query form ( info Archived 16 December 2017 at the Wayback Machine)
- Dictionary of Minor Planet Names, Google books
- Discovery Circumstances: Numbered Minor Planets (20001)-(25000) – Minor Planet Center
- 20461 Dioretsa at AstDyS-2, Asteroids—Dynamic Site
- 20461 Dioretsa at the JPL Small-Body Database