2015 KG163, also known as o5m52, is a trans-Neptunian object from the outermost region of the Solar System, approximately 102 kilometers (63 miles) in diameter. It was first observed on 24 May 2015, by astronomers of the Outer Solar System Origins Survey using the Canada–France–Hawaii Telescope at Mauna Kea Observatories, Hawaii, United States.[5] With an observation arc of 2 years, it passed perihelion around August 2022[7][a] at a velocity of 6.5 km/s with respect to the Sun.

2015 KG163
The orbit of 2015 KG163 (right side, in orange) and other extreme detached objects, along with the hypothetical Planet Nine's orbit on the right
Discovery[1]
Discovered byOSSOS
Discovery siteMauna Kea Obs.
Discovery date24 May 2015
Designations
2015 KG163
o5m52[2]
TNO[3] · detached[4] · distant[5]
Orbital characteristics (barycentric)[6]
Epoch 25 February 2023 (JD 2460000.5)
Uncertainty parameter 3[3]
Observation arc2.02 yr (739 days)
Earliest precovery date17 May 2015
Aphelion1319 AU
Perihelion40.493 AU
679.816 AU
Eccentricity0.94043
17713 yr
0.014°
0° 0m 0.2s / day
Inclination13.994°
219.103°
≈ 10 August 2022[7]
±2 months[a]
32.097°
Physical characteristics
65–150 km (est. 0.04–0.20)[8]
24.2 (discovery)[1]
8.2[3][5]

It is one a small number of detached objects with perihelion distances of 30 AU or more, and semi-major axes of 250 AU or more.[9] Such objects can not reach such orbits without some perturbing object, which lead to the speculation of Planet Nine. Its argument of perihelion is similar to that of 2013 FT28, but its semi-major axis is larger, such that its orbit may cross that of Planet Nine.

Closeup of current position near perihelion, passing downward from the upper left of this view

Notes

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  1. ^ a b Uncertainty in the perihelion date is 18 days (1-sigma) or 54 days (3-sigma) according to JPL's Small-Body Database.[3]

References

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  1. ^ a b "MPEC-2017-M23 : 2015 KG163". Minor Planet Electronic Circular. Minor Planet Center. 19 June 2017. Retrieved 5 July 2023.
  2. ^ Shankman, Cory; et al. (2017). "OSSOS. VI. Striking Biases in the Detection of Large Semimajor Axis Trans-Neptunian Objects". The Astronomical Journal. 154 (2): 50. arXiv:1706.05348. Bibcode:2017AJ....154...50S. doi:10.3847/1538-3881/aa7aed. hdl:10150/625487. S2CID 3535702.
  3. ^ a b c d "JPL Small-Body Database Browser: (2015 KG163)" (2017-05-25 last obs.). Jet Propulsion Laboratory. Retrieved 4 August 2022.
  4. ^ "List of known trans-Neptunian objects". Johnstonsarchive.net. 5 September 2016. Retrieved 1 November 2017.
  5. ^ a b c "2015 KG163". Minor Planet Center. Retrieved 1 November 2017.
  6. ^ "JPL Horizons On-Line Ephemeris for 2015 KG163 at epoch JD 2460000.5". JPL Horizons On-Line Ephemeris System. Jet Propulsion Laboratory. Retrieved 5 July 2023. Solution using the Solar System Barycenter. Ephemeris Type: Elements and Center: @0)
  7. ^ a b JPL Horizons Observer Location: @sun (perihelion occurs when deldot changes from negative to positive)
  8. ^ "Asteroid Size Estimator". Center for Near Earth Object Studies. Jet Propulsion Laboratory. Retrieved 5 July 2023.
  9. ^ "MPC-query: a>250 and q<30". Minor Planet Center. Retrieved 1 November 2017.
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