Summary for : (26308) 1998 SM165

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
TNO--- | --0.56 ± 0.24   (C)43 %284.9 ± 23.28.1 %6.78e+18 ± 2.40e+1835 %SEVM
TNO--- | --0.57 ± 0.20   (C)36 %283.9 ± 5.21.8 %6.78e+18 ± 2.40e+1835 %Sw.avg
TNO-0.56 ± 0.20   (C)36 %284.4 ± 5.11.8 %6.78e+18 ± 2.40e+1835 %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
(26308) 1998 SM165290.00 ± 36.0012.4 % NEATM2006D30 0.02 1
(26308) 1998 SM165279.79 ± 29.2910.5 % NEATM2008D51 0.03 2

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.


EVM diam. average D = (284.9 ± 23.17) km   (ΔD/D = 8%, SNR = 12.29) Derived bulk density ρ = (0.56 ± 0.24) g/cm3   (Δρ/ρ = 43%, SNR = 2.3)


References
D30(2006):Spencer, J.R., Stansberry, J.A., Grundy, W.M., Noll, K.S., 2006. A Low Density for Binary Kuiper Belt Object (26308) 1998 SM165, in: AAS/Division for Planetary Sciences Meeting Abstracts
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.

Mass estimates

DesignationMass / Err (kg)ΔM/MMethodYearRefNχ2Use
(26308) 1998 SM1656.78e+18 ± 2.40e+1835 %BinImg 2004M400.00 1

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 = (6.780 ± 2.400) × 1018 kg   (ΔM/M = 35%, SNR = 2.8) Derived bulk density ρ = (0.56 ± 0.24) g/cm3   (Δρ/ρ = 43%, SNR = 2.3)


References
M40(2004):Margot, J.L., Brown, M.E., Trujillo, C.A., Sari, R., 2004. HST observations of Kuiper Belt binaries, in: AAS/Division for Planetary Sciences Meeting Abstracts