28978 Ixion

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28978 Ixion
28978 Ixion
Discovery
Discovered by Deep Ecliptic Survey
Discovery date 22 May, 2001
Designations
MPC designation 28978 Ixion
Alternative names 2001 KX76
Minor planet category TNO (plutino)[1]
Orbital characteristics[2]
Epoch December 31, 2006 (JD 2 454 100.5)
Aphelion 7 370.503 Gm (49.269 AU)
Perihelion 4 501.495 Gm (30.091 AU)
Semi-major axis 5 935.999 Gm (39.680 AU)
Eccentricity 0.242
Orbital period 91 295.847 d (249.95 a)
Average orbital speed 4.66 km/s
Mean anomaly 268.546°
Inclination 19.584°
Longitude of ascending node 71.028°
Argument of perihelion 298.779°
Physical characteristics
Dimensions ~650+260−220 [3]
< 822 km diameter[4]
Surface area < 2.24×106 km²
Volume < 3.15×108 km³
Mass ≈3×1020? kg[5]
Mean density 2.0? g/cm³
Equatorial surface gravity < 0.229 7? m/s²
Escape velocity < 0.434 6? km/s
Rotation period ? d

28978 Ixion is a Kuiper belt object that was found on May 22, 2001. Ixion is a plutino (an object that has a 2:3 orbital resonance with Neptune) and could be a dwarf planet. Astronomers think that it has a diameter of about 800 km, which makes it the third biggest plutino. It is named after Ixion, a figure from Greek mythology. Before it was named Ixion, it had the provisional designation 2001 KX76.

References [change]

  1. Marc W. Buie (2007-07-12). "Orbit Fit and Astrometric record for 28978". SwRI (Space Science Department). http://www.boulder.swri.edu/~buie/kbo/astrom/28978.html. Retrieved 2008-09-29.
  2. 2.0 2.1 "JPL Small-Body Database Browser: 28978 Ixion (2001 KX76)". 2007-07-12 last obs. http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=Ixion. Retrieved 2008-10-04.
  3. John Stansberry, Will Grundy, Mike Brown, Dale Cruikshank, John Spencer, David Trilling, Jean-Luc Margot (2007). "Physical Properties of Kuiper Belt and Centaur Objects: Constraints from Spitzer Space Telescope". University of Arizona, Lowell Observatory, California Institute of Technology, NASA Ames Research Center, Southwest Research Institute, Cornell University. http://arxiv.org/abs/astro-ph/0702538v2. Retrieved 2008-11-17.
  4. 4.0 4.1 Wm. Robert Johnston. "TNO/Centaur diameters and albedos". http://www.johnstonsarchive.net/astro/tnodiam.html.
  5. Using the 2007 Spitzer spherical radius of 325 km; volume of a sphere * an assumed density of 2 g/cm³ yields a mass (m=d*v) of 2.8E+20 kg