Summary for : (50000) Quaoar

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
TNO--- | --2.46 ± 0.80   (C)33 %1050.4 ± 106.410.1 %1.49e+21 ± 1.75e+2012 %SEVM
TNO--- | --2.05 ± 0.98   (C)48 %1108.4 ± 174.815.8 %1.46e+21 ± 1.07e+207 %Sw.avg
TNO-3.60 ± 1.70   (C)47 %946.6 ± 137.314.5 %1.60e+21 ± 3.00e+2019 %C?

Average asteroid densities (g/cm^3):
C = 1.3 ± 0.6, B = 2.4 ± 0.5, S = 2.7 ± 0.5, M = 3.5 ± 1.0, P = 2.8 ± 1.6, X = 1.9 ± 0.8, Xc = 4.9 ± 0.9, Xk = 4.2 ± 0.7 (Ref)

Additional resources:
3D Model | JPL New Horizons | Minor Planet Center | Wikipedia (these auto-generated links might not work)

Note: The density estimates have been ranked from (A) to (E), corresponding to the relative error: (B) less than 20%, (C) between 20 and 50%, (D) between 50 and 100%, and (E) more than 100%. (A) stands for (presumably) reliable estimates (accuracy better than 20%), based on more than 5 mass estimates and 5 diameter estimates, or a spacecraft encounter. Apparently unrealistic densities (ρ > 8) are tagged with (X).

EVM: average by using the Expected Value Method (Ref). w.avg: weighted average (with w = 1/err^2).

T.T: Tholen Tax Class. T.B: Bus & Binzel Tax Class. T T.L: S3OS2 Lazarro (Tholen) Tax Class. T.L B: S3OS2 Lazarro (Bus & Binzel) Tax Class. T.D: DeMeo Tax Class.

Ref: S = SiMDA, C = Carry (2012)

Diameter estimates

DesignationDiameter / Err (km)ΔD/DMethodYearRefNχ2Use
(50000) Quaoar1260.00 ± 190.0015.1 % Img-PSF2004D132 1.22 1
(50000) Quaoar844.40 ± 198.1423.5 % NEATM2008D512 1.08 2
(50000) Quaoar908.00 ± 115.0012.7 % NEATM2009D532 1.53 3
(50000) Quaoar890.70 ± 70.007.9 % Img-PSF2010D652 5.20 4
(50000) Quaoar1110.00 ± 5.000.5 % Occ2013D105 142.23 5

plot, average diameter and derived density

All

Notes (N):
1: This estimate is discarded for the average diameter (and derived density) calculation in Carry (2012).
2: This estimate is discarded for the average diameter (and derived density) calculation in SiMDA (catalog).

Img-PSF : Profile deviation from a Point-Spread Function. NEATM : Near-Earth Asteroid Thermal Model. Occ : Stellar occultation.


EVM diam. average D = (1050.4 ± 106.37) km   (ΔD/D = 10%, SNR = 9.88) Derived bulk density ρ = (2.46 ± 0.80) g/cm3   (Δρ/ρ = 33%, SNR = 3.1)


References
D13(2004):Brown, M.E., Trujillo, C.A., 2004. Direct Measurement of the Size of the Large Kuiper Belt Object (50000) Quaoar. Astronomical Journal 127, 2413–2417.
D51(2008):Stansberry, J., Grundy, W., Brown, M.E., Cruikshank, D.P., Spencer, J.R., Trilling, D., Margot, J.L., 2008. Physical Properties of Kuiper Belt and Centaur Objects: Constraints from the Spitzer Space Telescope. The Solar System Beyond Neptune , 161–179.
D53(2009):Brucker, M.J., Grundy, W.M., Stansberry, J.A., Spencer, J.R., Sheppard, S.S., Chiang, E.I., Buie, M.W., 2009. High albedos of low inclination Classical Kuiper belt objects. Icarus 201, 284–294.
D65(2010):Fraser, W.C., Brown, M.E., 2010. Quaoar: A Rock in the Kuiper Belt. Astrophysical Journal 714, 1547–1550.
D105(2013):Braga-Ribas, F.; Sicardy, B.; Ortiz, J. L.; et al.; 2013.The Size, Shape, Albedo, Density, and Atmospheric Limit of Transneptunian Object (50000) Quaoar from Multi-chord Stellar Occultations. The Astrophysical Journal, Volume 773, Issue 1, article id. 26, 13 pp. (2013).

Mass estimates

DesignationMass / Err (kg)ΔM/MMethodYearRefNχ2Use
(50000) Quaoar1.60e+21 ± 3.00e+2019 %BinImg 2010M900.13 1
(50000) Quaoar1.40e+21 ± 2.00e+2014 %BinImg 2013M1300.21 2

plot, average mass and derived density

All

Notes (N):
1: This estimate is discarded for the average mass (and derived density) calculation in Carry (2012).
2: This estimate is discarded for the average mass (and derived density) calculation in SiMDA (catalog).
3: This estimate is an average of individual solutions listed before under the same reference (e.g. M125).

BinImg : Binary imaged at optical wavelength.


EVM mass average M = (1.491 ± 0.175) × 1021 kg   (ΔM/M = 12%, SNR = 8.5) Derived bulk density ρ = (2.46 ± 0.80) g/cm3   (Δρ/ρ = 33%, SNR = 3.1)


References
M90(2010):Fraser, W.C., Brown, M.E., 2010. Quaoar: A Rock in the Kuiper Belt. Astrophysical Journal 714, 1547–1550. [NOTE: the mass is the system mass]
M130(2013):Fraser, W. C., Batygin, K., Brown, M. E., et al., 2013. The mass, orbit, and tidal evolution of the Quaoar–Weywot system. Icarus, 222(1), 357-363. [NOTE: the system mass is given as 1.3-1.5 ± 0.1 e21 kg => 1.4 ± 0.2 used here per def.]