(668643) 2012 DR30

(668643) 2012 DR₃₀ is a trans-Neptunian object and centaur with an extremely eccentric orbit that brings it from 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.

(668643) 2012 DR₃₀

2012 DR30 in a precovery image taken by the Sloan Digital Sky Survey in 2000
Discovery[1]
Discovered by	PMO NEO Survey Program
Discovery site	Purple Mountain Obs.
Discovery date	6 February 2008
Designations
MPC designation	2012 DR30
Alternative designations	2012 DR30 2009 FW54
Minor planet category	TNO[2] centaur[3][4][5] damocloid distant[1]
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
Semi-major axis	1603.44 AU 1032 AU (barycentric)
Eccentricity	0.9909
Orbital period (sidereal)	64207 yr 33100 yr (barycentric)
Mean anomaly	0.0453°
Mean motion	0° 0m 0s / day
Inclination	77.986°
Longitude of ascending node	341.48°
Time of perihelion	≈ 16 March 2011[6]
Argument of perihelion	195.57°
Jupiter MOID	9.311 AU
Saturn MOID	5.45 AU[1]
Uranus MOID	3.32 AU[1]
TJupiter	0.9860
Physical characteristics
Mean diameter	185 km[4] 188 km[5]
Geometric albedo	0.076[5] 0.08 (approx.)[4]
Spectral type	BR–IR[5] B–V = 1.21[5]
Apparent magnitude	19.9[7]
Absolute magnitude (H)	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 out-gassing 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.

Orbital evolution
Year[a] (epoch)	Barycentric Aphelion (Q) (AU)	Orbital period years
1950	2000	32000
2050	2049	33100

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 (q_min) 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]

Archived data from the JPL SBDB and MPC.^[b][c]

Comparison

The orbits of Sedna, 2012 VP113, Leleākūhonua, and other very distant objects along with the predicted orbit of Planet Nine. The three sednoids (pink) along with the red-colored extreme trans-Neptunian object (eTNO) orbits are suspected to be aligned with the hypothetical Planet Nine while the blue-colored eTNO orbits are anti-aligned. The highly elongated orbits colored brown include centaurs and damocloids with large aphelion distances over 200 AU.

See also

• 2002 RN109
• 2005 VX3
• (308933) 2006 SQ372
• 2007 TG422
• 90377 Sedna
• List of hyperbolic comets
• Planet Nine

Notes

1. 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]
2. Archived JPL Small-Body Database Browser: (2012 DR30) from 15 October 2014.
3. Archived MPC object data for 2012 DR30 (2009 FW54) from 12 July 2013.

References

1. "2012 DR30". Minor Planet Center. Archived from the original on 15 February 2017. Retrieved 19 November 2018.
2. "JPL Small-Body Database Browser: (2012 DR30)" (2014-12-17 last obs.). Jet Propulsion Laboratory. Archived from the original on 27 July 2020. Retrieved 19 November 2018.
3. Marc W. Buie. "Orbit Fit and Astrometric record for 12DR30". SwRI – Space Science Department. Archived from the original on 5 February 2016. Retrieved 1 February 2016.
4. Kiss, Cs.; Szabó, Gy.; Horner, J.; Conn, B. C.; Müller, T. G.; Vilenius, E.; et al. (July 2013). "A portrait of the extreme solar system object 2012 DR30". Astronomy and Astrophysics. 555: 13. arXiv:1304.7112. Bibcode:2013A&A...555A...3K. doi:10.1051/0004-6361/201321147. S2CID 54021504.
5. Johnston, Wm. Robert (7 October 2018). "List of Known Trans-Neptunian Objects". Johnston's Archive. Archived from the original on 23 October 2019. Retrieved 19 November 2018.
6. JPL Horizons Archived 28 November 2020 at the Wayback Machine Observer Location: @sun
7. "AstDyS 2012DR30 Ephemerides". Department of Mathematics, University of Pisa, Italy. Archived from the original on 3 May 2024. Retrieved 14 February 2017. (Distance to Sun [R] from first day of 2016 to first day of 2020. Assuming average apparent magnitude for 2017.)
8. "JPL Small-Body Database Search Engine: Asteroids and a > 100 (AU)". JPL Solar System Dynamics. Archived from the original on 29 November 2020. Retrieved 15 October 2014.
9. Horizons output. "Barycentric Osculating Orbital Elements for 2012 DR30". Archived from the original on 28 November 2020. Retrieved 6 March 2014. (Solution using the Solar System Barycenter and barycentric coordinates. Select Ephemeris Type:Elements and Center:@0)
10. Kaib, Nathan A.; Becker, Andrew C.; Jones, R. Lynne; Puckett, Andrew W.; Bizyaev, Dmitry; Dilday, Benjamin; et al. (April 2009). "2006 SQ372: A Likely Long-Period Comet from the Inner Oort Cloud". The Astrophysical Journal. 695 (1): 268–275. arXiv:0901.1690. Bibcode:2009ApJ...695..268K. doi:10.1088/0004-637X/695/1/268. S2CID 16987581.

External links

• 2012 DR30 - Ein Transneptun mit ungewöhnlicher Bahn, www.spektrum.de, March 2012 (in German)
• Mysterious solar system object 2012 DR30: period ~50,000 years, inclination 75°, perihelion 14 AU
• Transneptunian Object 2012 DR30 – Is it a comet?
• Images 2012 DR30
• 2012 DR30 Archived 15 January 2020 at the Wayback Machine (Seiichi Yoshida)
• Webcite archive of Epoch 2016-Jan-13 with aphelion (Q) of 2789 AU
• (668643) 2012 DR30 at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• (668643) 2012 DR30 at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters