2007 TG422

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2007 TG422
Discovered by SDSS Collaboration
A. C. Becker,
A. W. Puckett,
J. Kubica
Apache Point (705)
Discovery date 2007-10-03
MPC designation 2007 TG422
Orbital characteristics[4]
Epoch 2011-Feb-08
Aphelion 967 AU (Q)[3][a]
(Heliocentric 1087 AU)
Perihelion 35.560 AU (q)
501 AU (a)[3][a]
(Heliocentric 561.4 AU)
Eccentricity 0.9366
11,200 yr[3][a]
(Heliocentric 13304 yr)
0.143° (M)
Inclination 18.59°
112.8° (Ω)
285.6° (ω)
Physical characteristics
Dimensions 343 km (assumed)[5]
150–340 km[4][6]
270 km[7][8]
Albedo 0.04 (expected)[5]
Spectral type

2007 TG422, also written as 2007 TG422, is a scattered-disc object with a perihelion distance of 35.6 AU, which is just inside the influence of Neptune,[2] and an aphelion distance similar to 90377 Sedna's.


Mike Brown's website lists it as a possible dwarf planet with a diameter of 343 km based on an assumed albedo of 0.04.[5] The albedo is expected to be low because the object has a blue (neutral) color.[5] But if the albedo is higher the object could easily be much smaller. Assuming a generic trans-Neptunian albedo of 0.09, it is about 270 km in diameter.[7] But because the true albedo is unknown and it has an absolute magnitude (H) of 6.2,[4] it could be anywhere from about 150 to 340 km in diameter.[6]


2007 TG422 came to perihelion in 2005 at a heliocentric distance of 35.5 AU,[4] and is currently 36.6 AU from the Sun.[9]

Given the orbital eccentricity of this object, different epochs can generate quite different heliocentric unperturbed two-body best-fit solutions to the aphelion distance (maximum distance) of this object.[b] With a 2007 epoch the object had an approximate period of about 10,611 years with aphelion at 930 AU.[2] But using a 2011 epoch shows a period of about 13,304 years with aphelion at 1087 AU.[4] For objects at such high eccentricity, the Sun's barycentric coordinates are more stable than heliocentric coordinates.[10] Using JPL Horizons with an observed orbital arc of only 2 years, the barycentric orbital elements for epoch 2008-May-14 generate a semi-major axis of 501 AU and a period of 11,200 years.[3] For comparison, probable dwarf planet Sedna has a barycentric semi-major axis of 506 AU and a period of 11,400 years.[3] Both (308933) 2006 SQ372 and (87269) 2000 OO67 take longer than Sedna and 2007 TG422 to orbit the Sun using barycentric coordinates.

2007 TG422 has been observed 34 times over five years and has an uncertainty parameter of 2.[4]


  1. ^ a b c Solution using the Solar System's barycenter
  2. ^ Read osculating orbit for more details about heliocentric unperturbed two-body solutions


  1. ^ "MPEC 2008-D39: 2007 TG422, 2007 TH422, 2007 TJ422, 2007 UL126, 2007 VH305". IAU Minor Planet Center. 2008-02-26. Retrieved 2011-01-30.  K07Tg2G
  2. ^ a b c Marc W. Buie. "Orbit Fit and Astrometric record for 07TG422" (2009-09-28 using 32 of 32 observations). SwRI (Space Science Department). Retrieved 2011-01-30. 
  3. ^ a b c d e Horizons output (2011-01-30). "Barycentric Osculating Orbital Elements for 2007 TG422". Retrieved 2011-01-30.  (Horizons)
  4. ^ a b c d e f g "JPL Small-Body Database Browser: (2007 TG422)" (2013-01-12 last obs). Retrieved 2011-01-30. 
  5. ^ a b c d e Michael E. Brown. "How many dwarf planets are there in the outer solar system? (updates daily)". California Institute of Technology. Retrieved 2014-02-16. 
  6. ^ a b "Absolute Magnitude (H)". NASA/JPL. Archived from the original on 26 November 2009. Retrieved 2009-12-06. 
  7. ^ a b Dan Bruton. "Conversion of Absolute Magnitude to Diameter for Minor Planets". Department of Physics & Astronomy (Stephen F. Austin State University). Retrieved 2011-01-30. 
  8. ^ Assuming an albedo of 0.09
  9. ^ a b "AstDyS 2007TG422 Ephemerides". Department of Mathematics, University of Pisa, Italy. Retrieved 2014-04-05. 
  10. ^ Kaib, Nathan A.; Becker, Andrew C.; Jones, R. Lynne; Puckett, Andrew W.; Bizyaev, Dmitry; Dilday, Benjamin; Frieman, Joshua A.; Oravetz, Daniel J.; Pan, Kaike; Quinn, Thomas; Schneider, Donald P.; Watters, Shannon (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. 

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