(225088) 2007 OR10

From Infogalactic: the planetary knowledge core
Jump to: navigation, search
(225088) 2007 OR10
2007 OR10 and its moon.png
2007 OR10 and its moon seen by the Hubble Space Telescope in 2010
Discovery [1]
Discovered by M. E. Schwamb
M. E. Brown
D. L. Rabinowitz
Discovery site Palomar Obs.
Discovery date 17 July 2007 [lower-alpha 1]
Designations
TNO [2] · SDO [3] · 3:10 res.[4]
Orbital characteristics [2]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 4
Observation arc 30.09 yr (10,989 days)
Aphelion 101.02 AU
Perihelion 33.102 AU
67.059 AU
Eccentricity 0.5064
549.16 yr (200,579 days)
104.43°
Inclination 30.904°
336.82°
207.04°
Known satellites 1[5]
Physical characteristics
Dimensions 1535+75
−225 km[6][7]
1280+210
−210 km[8]
Mass ~1.3–6 × 1021 kg (est.)
44.81±0.37 h[6][7]
0.089+0.031
−0.009[6][7]
0.185+0.076
−0.052[8]
Temperature 31 K[9]
red[10]
21.4[11]
1.8[2] 1.8[12]
2.34[6]

(225088) 2007 OR10 is a trans-Neptunian object (TNO) orbiting the Sun in the scattered disc, approximately 1500 kilometers in diameter. It is the third-largest known body in the Solar System beyond the orbit of Neptune,[6][7][13] and continues to be the largest known body in the Solar System without a name.[14] According to estimates as of May 2016, it is slightly larger than Makemake or Haumea, and is hence almost certainly a dwarf planet. It has one known moon.[5]

History

Discovery

(225088) 2007 OR10 was discovered by California Institute of Technology astronomers as part of the PhD thesis of Megan E. Schwamb, then a graduate student of Michael E. Brown.[15]

Naming

Brown nicknamed the object "Snow White" for its presumed white color,[15] because it would have to be very large or very bright to be detected by their survey.[14] By that time, Brown's team had already discovered "seven dwarves": Quaoar in 2002, Sedna in 2003, Haumea, Salacia and Orcus in 2004, and Makemake and Eris in 2005. However, 2007 OR10 turned out to be one of the reddest objects in the Kuiper belt, comparable only to Quaoar, so the nickname was dropped.

2007 OR10 is currently the largest known object in the Solar System without an official name. In 2011 Brown decided he finally had enough information to justify giving it one, because the discovery of water ice and the possibility of methane makes it noteworthy enough to warrant further study.[15] However, as of 2017, Brown had yet to propose a name, though he notes that in November 2019 anyone will be able to make a proposal.[16]

Distance

(225088) 2007 OR10 came to perihelion around 1857.[2] As of February 2016 it is located 87.5 AU from the Sun[17] and moving at 2.7 kilometers per second (6,000 miles per hour) with respect to the Sun.[18] This makes it the fourth-farthest known large body in the Solar System, after V774104 (103 au), Eris (96.3 au), 2014 UZ224 (91.4 au), and farther out than Sedna (85.7 au) as of 4 February 2017.[14] It has been farther from the Sun than Sedna since 2013.[18] 2007 OR10 will be farther than both Sedna and Eris by 2045,[19] and it will reach aphelion in 2130.[18]

Absolute magnitude

The size of an object can be calculated from its absolute magnitude (H) and the albedo (the amount of light it reflects). 2007 OR10 has an absolute magnitude (H) of 1.92,[2] which makes it the fifth-brightest TNO known,[20] a little less bright than Sedna (H=1.5; D≈1,000 km)[21] and brighter than Orcus (H=2.2; D≈800 km).[22]

2007 OR10 is among the reddest objects known.[10] This is probably in part due to methane frosts, which turn red when bombarded by sunlight and cosmic rays.[10]

Surface composition and atmosphere

The spectrum of 2007 OR10 shows signatures for both water ice and methane, which makes it similar in composition to Quaoar. The presence of red methane frost on the surfaces of both 2007 OR10 and Quaoar implies the existence of a tenuous methane atmosphere on both objects, slowly evaporating into space. Although 2007 OR10 comes closer to the Sun than Quaoar, and is thus warm enough that a methane atmosphere should evaporate, its larger mass makes retention of an atmosphere just possible.[10] In particular, 2007 OR10's large size means that it is likely to retain even nitrogen, which almost all TNOs lose over the course of their existence.[23] The presence of water ice on the surface of 2007 OR10 implies a brief period of cryovolcanism in its distant past.[24]

Orbit

Earth Dysnomia Dysnomia Eris Eris Charon Charon Nix Nix Kerberos Kerberos Styx Styx Hydra Pluto Pluto Makemake Makemake Namaka Namaka Hi'iaka Hi'iaka Haumea Haumea Sedna Sedna 2007 OR10 2007 OR10 Weywot Weywot Quaoar Quaoar Vanth Vanth Orcus Orcus File:EightTNOs.png
Artistic comparison of Pluto, Eris, Makemake, Haumea, Sedna, 2007 OR10, Quaoar, Orcus, and Earth.
(
This box:
)

The Deep Ecliptic Survey (DES) shows the orbit to be in a 3:10 resonance with Neptune.[4] The MPC lists it as a scattered-disc object.[3] 2007 OR10 was discovered when searching for objects in the region of Sedna.[25]

2007 OR10 has been observed 46 times over seven oppositions with a precovery image from 1985.[2]

It was formally announced on 7 January 2009.[1]

The orbit of 2007 OR10 compared to the orbit of Eris, Pluto, and the outer planets
Resonance. A preliminary motion analysis of 2007 OR10 librating in a 3:10 resonance with Neptune. The animated GIF consists of 16 frames covering 26,000 years.[4] Neptune is held stationary.

Dwarf-planet status

Based on the most recent size estimates as of May 2016,[7] 2007 OR10 would be the third-largest dwarf planet, after Pluto and Eris, and before Makemake, Haumea, and Ceres, though the error bars overlap with those of Makemake. The IAU has not addressed the possibility of accepting additional dwarf planets since before the discovery of 2007 OR10 was announced. Brown states that it "must be a dwarf planet even if predominantly rocky",[26] and Scott Sheppard and colleagues think that it is "likely" to be a dwarf planet,[27] based on its minimum possible diameter (552 km)[28] and what is understood of the conditions for hydrostatic equilibrium in cold icy–rocky bodies. 2007 OR10 is too distant for its diameter to be resolved directly; Brown's estimate of 1,000–1,500 km is based on calculating the albedo that is the best fit in his model,[10] which agrees with the 1280±210 km determined from observations by the Herschel space observatory.[8] Updated thermal modeling put the size into the 1500 km range with a comparatively low albedo of 8%.[6] If the orbit of 2007 OR10's small satellite (see below) can be well determined, its mass could be calculated directly; mass is also a factor in hydrostatic equilibrium.

Satellite

Moon around dwarf planet 2007 OR10.[29]

The slow rotation rate of 2007 OR10, compared to the other TNOs, raised the possibility of a satellite that slowed down the rotation via tidal dissipation. In 2016, analysis of Hubble images of 2007 OR10 taken in 2010 revealed a satellite around 300 km in diameter and orbiting at a distance of at least 15,000 km. It was announced at the DPS48 meeting on 17 October 2016.[5][30] The satellite is probably too small and dark to affect size estimates for 2007 OR10.[5] Further analysis from May 2017 confirms this orbiting moon.[31][32]

See also

Notes

  1. ↑ Discovery was announced two years later on 7 January 2009

References

  1. ↑ 1.0 1.1 Lua error in package.lua at line 80: module 'strict' not found.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Lua error in package.lua at line 80: module 'strict' not found.
  3. ↑ 3.0 3.1 Lua error in package.lua at line 80: module 'strict' not found.
  4. ↑ 4.0 4.1 4.2 Lua error in package.lua at line 80: module 'strict' not found.
  5. ↑ 5.0 5.1 5.2 5.3 Lua error in package.lua at line 80: module 'strict' not found.
  6. ↑ 6.0 6.1 6.2 6.3 6.4 6.5 Lua error in package.lua at line 80: module 'strict' not found.
  7. ↑ 7.0 7.1 7.2 7.3 7.4 Lua error in package.lua at line 80: module 'strict' not found.
  8. ↑ 8.0 8.1 8.2 Lua error in package.lua at line 80: module 'strict' not found.
  9. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  10. ↑ 10.0 10.1 10.2 10.3 10.4 Lua error in package.lua at line 80: module 'strict' not found.
  11. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  12. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  13. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  14. ↑ 14.0 14.1 14.2 Lua error in package.lua at line 80: module 'strict' not found.
  15. ↑ 15.0 15.1 15.2 Lua error in package.lua at line 80: module 'strict' not found.
  16. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  17. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  18. ↑ 18.0 18.1 18.2 Lua error in package.lua at line 80: module 'strict' not found.
  19. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  20. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  21. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  22. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  23. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  24. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  25. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  26. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  27. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  28. ↑ 1329×10(−H/5)
  29. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  30. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  31. ↑ NASA/Goddard Space Flight Center. (2017, May 18). Moon orbits third largest dwarf planet in our solar system. ScienceDaily. Retrieved May 19, 2017 from www.sciencedaily.com/releases/2017/05/170518140249.htm
  32. ↑ Kiss, C. et al., 2017, "Discovery of a Satellite of the Large Trans-Neptunian Object (225088) 2007 OR10", The Astrophysical Journal Letters, Volume 838, Issue 1, article id. L1 http://adsabs.harvard.edu/abs/2017ApJ...838L...1K

External links

Retrieved from "https://infogalactic.com/w/index.php?title=(225088)_2007_OR10&oldid=725250186"