Summary for : (90482) Orcus

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
TNO--- | --1.56 ± 0.22   (B)14 %919.2 ± 43.54.7 %6.33e+20 ± 3.31e+181 %SEVM
TNO--- | --1.56 ± 0.16   (B)10 %918.7 ± 31.53.4 %6.32e+20 ± 6.12e+181 %Sw.avg
TNO-1.57 ± 0.22   (B)14 %915.5 ± 42.64.7 %6.34e+20 ± 3.00e+180 %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
(90482) Orcus946.29 ± 73.197.7 % NEATM2008D51 0.14 1
(90482) Orcus940.00 ± 70.007.4 % NEATM2010D63 0.09 2
(90482) Orcus850.00 ± 85.0010.0 % TPM2010D60 0.66 3

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).

NEATM : Near-Earth Asteroid Thermal Model. TPM : Thermophysical Model.


EVM diam. average D = (919.2 ± 43.50) km   (ΔD/D = 5%, SNR = 21.13) Derived bulk density ρ = (1.56 ± 0.22) g/cm3   (Δρ/ρ = 14%, SNR = 7.0)


References
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.
D60(2010):Lim, T.L., Stansberry, J., Müller, T.G., Mueller, M., Lellouch, E., Kiss, C., Santos-Sanz, P., Vilenius, E., Protopapa, S., Moreno, R., Delsanti, A., Duffard, R., Fornasier, S., Groussin, O., Harris, A.W., Henry, F., Horner, J., Lacerda, P., Mommert, M., Ortiz, J.L., Rengel, M., Thirouin, A., Trilling, D., Barucci, A., Crovisier, J., Doressoundiram, A., Dotto, E., Gutiérrez Buenestado, P.J., Hainaut, O.R., Hartogh, P., Hestroffer, D., Kidger, M., Lara, L.M., Swinyard, B.M., Thomas, N., 2010. “TNOs are Cool”: A survey of the trans-Neptunian region . III. Thermophysical properties of 90482 Orcus and 136472 Makemake. Astronomy and Astrophysics 518, L148.
D63(2010):Brown, M.E., Ragozzine, D., Stansberry, J., Fraser, W.C., 2010. The Size, Density, and Formation of the Orcus-Vanth System in the Kuiper Belt. Astronomical Journal 139, 2700–2705.

Mass estimates

DesignationMass / Err (kg)ΔM/MMethodYearRefNχ2Use
(90482) Orcus6.32e+20 ± 1.00e+180 %BinImg 2010M872.11 1
(90482) Orcus6.41e+20 ± 5.00e+181 %BinImg 2011M942.28 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 = (6.335 ± 0.033) × 1020 kg   (ΔM/M = 1%, SNR = 191.3) Derived bulk density ρ = (1.56 ± 0.22) g/cm3   (Δρ/ρ = 14%, SNR = 7.0)


References
M87(2010):Brown, M.E., Ragozzine, D., Stansberry, J., Fraser, W.C., 2010. The Size, Density, and Formation of the Orcus-Vanth System in the Kuiper Belt. Astronomical Journal 139, 2700–2705.
M94(2011):Carry, B., Hestroffer, D., DeMeo, F.E., Thirouin, A., Berthier, J., Lacerda, P., Sicardy, B., Doressoundiram, A., Dumas, C., Farrelly, D., Müller, T.G., 2011. Integral-field spectroscopy of (90482) Orcus-Vanth. Astronomy and Astrophysics 534, A115.