(668643) 2012 DR30
Trans-Neptunian object and centaur
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(668643) 2012 DR30 is a trans-Neptunian object and centaur with an extremely eccentric orbit that brings it from the inner Oort cloud, the outermost region of the Solar System. It was discovered on 6 February 2008 by astronomers at Purple Mountain Observatory in Nanking, China.[1] It measures approximately 188 kilometers (120 miles) in diameter.
| Discovery[1] | |
|---|---|
| Discovered by | PMO NEO Survey Program |
| Discovery site | Purple Mountain Obs. |
| Discovery date | 6 February 2008 |
| Designations | |
| 2012 DR30 | |
| |
| Orbital characteristics[2][a] | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Uncertainty parameter 1 | |
| Observation arc | 14.72 yr (5,375 d) |
| Aphelion | 3192 AU 2049 AU (barycentric) |
| Perihelion | 14.5 AU |
| 1603.44 AU 1032 AU (barycentric) | |
| Eccentricity | 0.9909 |
| 64207 yr 33100 yr (barycentric) | |
| 0.0453° | |
| 0° 0m 0s / day | |
| Inclination | 77.986° |
| 341.48° | |
| ≈ 16 March 2011[6] | |
| 195.57° | |
| Jupiter MOID | 9.311 AU |
| Saturn MOID | 5.45 AU[1] |
| Uranus MOID | 3.32 AU[1] |
| TJupiter | 0.9860 |
| Physical characteristics | |
| 19.9[7] | |
| 7.1[2][1] | |
Description
Using an epoch of February 2017, it has the second-largest heliocentric semi-major axis of a minor planet not detected outgassing like a comet.[8] (2014 FE72 has a larger heliocentric semi-major axis.) 2012 DR30 does have a barycentric semi-major axis of 1032 AU.[9][a] For the epoch of July 2018 2012 DR30 will have its largest heliocentric semi-major axis of 1644 AU.
2012 DR30 passed 5.7 AU from Saturn in February 2009 and came to perihelion in March 2011 at a distance of 14.5 AU from the Sun (inside the orbit of Uranus).[2] In 2018, it will move from 18.2 AU to 19.1 AU from the Sun.[7] It comes to opposition in late March. With an absolute magnitude (H) of 7.1,[1] the object has a published diameter of 185 and 188 kilometers, respectively.[4][5]
With an observation arc of 14.7 years,[2] it has a well constrained orbit. It will not be 50 AU from the Sun until 2047. After leaving the planetary region of the Solar System, 2012 DR30 will have a barycentric aphelion of 2049 AU with an orbital period of 33100 years.[a] In a 10 million year integration of the orbit, the nominal (best-fit) orbit and both 3-sigma clones remain outside 12.2 AU (qmin) from the Sun.[3] Summary of barycentric orbital parameters are:
- Semi-major axis: ~1032 AU[a]
- aphelion: ~2049 AU[a]
- period: ~33,100 yr[a]
Comparison

See also
Notes
- Given the orbital eccentricity of this object, different epochs can generate quite different heliocentric unperturbed two-body best-fit solutions to the semi-major axis and orbital period. For objects at such high eccentricity, the Sun's barycenter is more stable than heliocentric coordinates.[10] Using JPL Horizons, the barycentric semi-major axis is approximately 1032 AU.[9]
- Archived JPL Small-Body Database Browser: (2012 DR30) from 15 October 2014.
- Archived MPC object data for 2012 DR30 (2009 FW54) from 12 July 2013.