Quaoar

For the Tongva god after which the object is named, see Chinigchinix. Not to be confused with Quasar.

50000 Quaoar
Low-resolution Hubble Space Telescope image of Quaoar and its moon Weywot, February 2006
Discovery[1]
Discovered by
Discovery sitePalomar Observatory
Discovery date4 June 2002
Designations
(50000) Quaoar
Pronunciation/ˈkwɑːwɑːr/, /ˈkwɑːoʊ.ɑːr/
Named after
Qua-o-ar / Kwawar[2]
(deity of the Tongva people)
2002 LM60
AdjectivesQuaoarian
Symbol🝾 (mostly astrological)
Orbital characteristics[3]
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 3
Observation arc65.27 yr (23,839 d)
Earliest precovery date25 May 1954
Aphelion45.488 AU (6.805 Tm)
Perihelion41.900 AU (6.268 Tm)
43.694 AU (6.537 Tm)
Eccentricity0.04106
288.83 yr (105,495 d)
301.104°
0° 0m 12.285s / day
Inclination7.9895°
188.927°
≈ 11 February 2075[6]
±17 days
147.480°
Known satellites1 (Weywot)
Physical characteristics
Dimensions1,286 × 1,080 × 932 km[a][7]
1,090±40 km (2024; volume equivalent)[7]
545±20 km (2024; volume equivalent)[7]
3.78×106 km2[8]
Volume6.78×108 km3[9]
Mass(1.20±0.05)×1021 kg[10]: 3 
Mean density
1.66–1.77 g/cm3[7]
Equatorial surface gravity
0.31 m/s2 at poles
to 0.16 m/s2 at longest axis
Equatorial escape velocity
0.59 km/s at poles
to 0.5 km/s at longest axis
17.6788±0.0004 h[11][10]
13.6°[b] or 14.0°[c] to ecliptic (if coplanar with rings)
North pole right ascension
258.47°±0.87°[10]: 3  or 259.82°±0.23°[13]: 4  (outer ring)
North pole declination
+54.14°±0.11°[10]: 3  or +53.45°±0.30°[13]: 4  (outer ring)
0.124±0.006[13]
Temperature≈ 44 K[14]
IR (moderately red)
B–V=0.94±0.01[15][16]
V−R=0.64±0.01[15]
V−I=1.28±0.02[16][17]
19.0[18]
2.737±0.008[18]
2.4 (assumed)[3][1]
40.4±1.8 milliarcseconds[19]

Quaoar (minor-planet designation: 50000 Quaoar) is a large, ringed dwarf planet in the Kuiper belt, a region of icy planetesimals beyond Neptune. It has an elongated ellipsoidal shape with an average diameter of 1,090 km (680 mi), about half the size of the dwarf planet Pluto. The object was discovered by American astronomers Chad Trujillo and Michael Brown at the Palomar Observatory on 4 June 2002. Quaoar's surface contains crystalline water ice and ammonia hydrate, which suggests that it might have experienced cryovolcanism. A small amount of methane is present on its surface, which can only be retained by the largest Kuiper belt objects.

Quaoar has one known moon, Weywot, which was discovered by Brown in February 2007.[20] Both objects were named after mythological figures from the Native American Tongva people in Southern California. Quaoar is the Tongva creator deity and Weywot is his son. In 2023, astronomers announced the discovery of two thin rings orbiting Quaoar outside its Roche limit, which defies theoretical expectations that rings outside the Roche limit should not be stable.[13]

  1. ^ a b c Cite error: The named reference MPC-object was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference Schmadel2006 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference jpldata was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Buie was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference MPEC-2008-O05 was invoked but never defined (see the help page).
  6. ^ JPL Horizons Archived 9 May 2021 at the Wayback Machine Observer Location: @sun (Perihelion occurs when deldot changes from negative to positive. Uncertainty in time of perihelion is 3-sigma.)
  7. ^ a b c d Cite error: The named reference Kiss2024 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Wolfram-SA was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Wolfram-V was invoked but never defined (see the help page).
  10. ^ a b c d e Cite error: The named reference Morgado2023 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Ortiz2003 was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference coordstransform was invoked but never defined (see the help page).
  13. ^ a b c d e Cite error: The named reference Pereira2023 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Fraser2013b was invoked but never defined (see the help page).
  15. ^ a b Cite error: The named reference Tegler2007 was invoked but never defined (see the help page).
  16. ^ a b Cite error: The named reference Belskaya2015 was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference lcdb was invoked but never defined (see the help page).
  18. ^ a b Cite error: The named reference Grundy-orbits was invoked but never defined (see the help page).
  19. ^ Cite error: The named reference Brown2004 was invoked but never defined (see the help page).
  20. ^ Cite error: The named reference IAUC8812 was invoked but never defined (see the help page).


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