Weywot (moon)

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(50000) Quaoar I (Weywot)
Quaoar and Weywot
Artist's impression of Quaoar and Weywot
Provisional or systematic name S / 2007 (50000) 1
Central body (50000) Quaoar
Properties of the orbit
Major semi-axis approx. 13,800 km
Periapsis ~ 11,758 km
Apoapsis ~ 15,842 km
eccentricity 0.148 ± 0.025
Orbit inclination Two solutions:

(14 ± 4) or (150 ± 4) °

Orbital time 12.438 ± 0.005 d
Mean orbital velocity 0.0424 km / s
Physical Properties
Albedo
Apparent brightness ~ 24.9 likes
Medium diameter km
Dimensions ≈ 8.5  ·  10 17 ? kg
Medium density ≈ 2.8 to 4.2 g / cm 3
discovery
Explorer
Date of discovery February 14, 2006

Weywot is a moon of the Kuiper belt - asteroids , cubewanos and dwarf planets - candidates (50,000) Quaoar . Its mean diameter is an estimated 81 kilometers.

Discovery and naming

Weywot was discovered on February 14, 2006 by Michael E. Brown and Terry-Ann Suer through observations of Quaoar with the Hubble Space Telescope . Weywot was found at 0.35 arc seconds from Quaoar, with an apparent magnitude difference of 5.6 ± 0.2. The discovery was announced on February 22, 2007; the moon was given the provisional designation S / 2007 (50000) 1 .

Brown left the choice of name to the Tongva , who chose the god Weywot , the son of Quaoar. Weywot was created through the singing of Quaoar. The name was mentioned on October 4, 2009 in MPC 67220 and officially published by the International Astronomical Union (IAU) on November 11, 2009 in IAUC 9094.

Track properties

Weywot orbits Quaoar in a slightly elliptical orbit at an average distance of around 13,800 kilometers from its center (24.84 Quaoar radii and 340.74 Weywot radii). The orbital eccentricity is 0.14. There are two possible solutions for the orbit inclination : Either a prograd orbit with 14 ° or a retrograde orbit with an inclination of 30 ° or 150 °.

Weywot orbits Quaoar in 12 days, 3 hours and 18.7 minutes, which corresponds to around 8480.9 orbits in a Quaoar year (around 288.81 earth years).

Michael Brown believes that the moon was formed by an impact on Quaoar, in which Quaoar lost a significant part of its ice mantle. The mass of Weywot is estimated to be about 1/2000 that of Quaoar.

Physical Properties

Assuming the same albedo and the same density as Quaoar, one can deduce a diameter of about 81 ± 11 kilometers, which corresponds to about a tenth of the diameter of Quaoar. Weywot is probably composed of the same material as quaoar, from large amounts of water ice as well as methane and other frozen gases that enclose a rock core.

From the surface of Quaoar, Weywot would have an angular diameter of 15.9 to 21.4 arc minutes at its zenith. In comparison, the size of the Earth's moon varies between 29.4 and 33.5 arc minutes from Earth. Its apparent brightness would be −3, comparable to Jupiter in its maximum brightness.

Provisions of the diameter for Weywot
year Dimensions km source
2009? 95 ± 24 Johnston
2010 74.2 Frasier et al. a.
2013 81.0 ± 11.0 Fornasier et al. a.
2014 <69.0 Thirouin et al. a.
2017 82.0 ± 17.0 Brown et al. a.
The most precise determination is marked in bold .

exploration

Since its discovery in 2006, Weywot could only be observed through earth-based telescopes and its orbital elements could be determined.

See also

Web links

Individual evidence

  1. ^ Johnston: (50,000) Quaoar and Weywot
  2. ↑ W. Frasier et al. a .: Quaoar: A rock in the Kuiper belt (May 2010)
  3. ↑ S. Fornasier et al. a .: TNOs are Cool: A survey of the trans-Neptunian region. VIII. Combined Herschel PACS and SPIRE observations of nine bright targets at 70-500 μm (July 2013)
  4. ↑ A. Thirouin et al. a .: Rotational properties of the binary and non-binary populations in the trans-Neptunian belt (July 2014)
  5. ↑ M. Brown et al. a .: The density of mid-sized Kuiper belt objects from ALMA thermal observations (February 2017)