20000 Varuna

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20000 Varuna Varuna symbol (bold).svg
20000-varuna hst.jpg

Hubble Space Telescope image of Varuna
Discovered byR. McMillan (Spacewatch)
Discovery date28 November 2000
MPC designation20000 Varuna
2000 WR106
TNO (cubewano)[1]
Orbital characteristics
Epoch 14 July 2004 (JD 2453200.5)
Aphelion6 781.985 Gm (45.335 AU)
Perihelion6 120.810 Gm (40.915 AU)
6 451.398 Gm (43.129 AU)
103 440.6 d (283.20 a)
4.53 km/s
Physical characteristics
Dimensions800 km (avg of thermals)[2]
(scalene ellipsoid)?[3][4]
Mass≈3.7×1020? kg[3][5]
Mean density
0.992 g/cm³[3]
0.15 m/s²
0.39 km/s
0.132 16 d (3.17 h)
Temperature≈43–41 K
Spectral type
(moderately red) B-V=0.93 V-R=0.64[6]
19.9 (opposition)[7]

20000 Varuna is a big Kuiper belt object (KBO). It could be a dwarf planet. Before it was named Varuna, it had the provisional designation 2000 WR106.

Varuna is named after the Hindu deity Varuṇa.

Physical characteristics[change | change source]

Varuna completes one rotation in about 3.17 hours (or 6.34 hours, depending on whether the light curve is single or double-peaked). Given the fast rotation, which is not common for objects so big, Varuna is thought to be a stretched spheroid, with a density around 1g/cm³ (close to the density of water).[4]

The surface of Varuna is somewhat red and small amounts of water ice have been found on its surface.[9]

References[change | change source]

  1. Marc W. Buie (2007-01-12). "Orbit Fit and Astrometric record for 20000". SwRI (Space Science Department). Retrieved 2008-09-19.
  2. 2.0 2.1 Stansberry (2008). "TNO/Centaur diameters and albedos". Retrieved 2006-11-08.
  3. 3.0 3.1 3.2 Lightcurves Lacerda P., Jewitt D. Dentisities Of Solar System Objects From Their Rotational Lightcurves", accepted to AJ Dec. 2006 Preprint
  4. 4.0 4.1 Jewitt D, Sheppard S (2002). "Physical Properties Of Trans-Neptunian Object (20000) Varuna". Astronomical Journal. 123 (April): 2110–2120. doi:10.1086/339557. S2CID 16543165. Preprint on arXiv.
  5. Calculated using Lacerda and Jewitt (2007) diameter of 900 km and density of 0.992 g/cm³.
  6. "TNO and Centaur Colors". Archived from the original on 2006-09-08. Retrieved 2006-11-08.
  7. "HORIZONS Web-Interface". JPL Solar System Dynamics. Retrieved 2008-07-02.
  8. "JPL Small-Body Database Browser: 20000 Varuna (2000 WR106)". 2007-11-17. Retrieved 2008-07-02.
  9. Licandro J, Oliva E, Di Martino M (2001). "NICS-TNG infrared spectroscopy of trans-neptunian objects 2000 EB173 and 2000 WR106". Astronomy & Astrophysics. 373 (July): 29–32L. doi:10.1051/0004-6361:20010758. S2CID 15690206.{{cite journal}}: CS1 maint: multiple names: authors list (link)

Other websites[change | change source]