Summary for : (66391) 1999 KW4

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
NEA--- | --1.95 ± 0.16   (B)8 %1.3 ± 0.02.3 %2.35e+12 ± 9.94e+104 %SEVM
NEA--- | --1.95 ± 0.16   (B)8 %1.3 ± 0.02.3 %2.35e+12 ± 9.94e+104 %Sw.avg
NEAS1.80 ± 0.29   (B)16 %1.3 ± 0.02.3 %2.35e+12 ± 1.00e+114 %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)

(Indirect) density estimates

Density (g/cm^3)Δρ/ρMethodYearRefN
1.2 ± 0.8066.7 %PheMu2009BD11

PheMu : Mutual eclipsing phenomena in binary systems.
References
BD11(2009):Scheirich, P., Pravec, P., 2009. Modeling of lightcurves of binary asteroids. Icarus 200, 531-547.

Diameter estimates

DesignationDiameter / Err (km)ΔD/DMethodYearRefNχ2Use
(66391) 1999 KW41.32 ± 0.032.3 % Radar2006D37 0.00 1

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).

Radar : Radar imaging.


EVM diam. average D = (1.3 ± 0.03) km   (ΔD/D = 2%, SNR = 44.00) Derived bulk density ρ = (1.95 ± 0.16) g/cm3   (Δρ/ρ = 8%, SNR = 12.5)


References
D37(2006):Ostro, S.J., Margot, J.L., Benner, L.A.M., Giorgini, J.D., Scheeres, D.J., Fahnestock, E.G., Broschart, S.B., Bellerose, J., Nolan, M.C., Magri, C., Pravec, P., Scheirich, P., Rose, R., Jurgens, R.F., De Jong, E.M., Suzuki, S., 2006. Radar Imaging of Binary Near-Earth Asteroid (66391) 1999 KW4. Science 314, 1276–1280.

Mass estimates

DesignationMass / Err (kg)ΔM/MMethodYearRefNχ2Use
(66391) 1999 KW42.35e+12 ± 9.94e+104 %BinRad 2006M610.00 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).

BinRad : Binary imaged with radar.


EVM mass average M = (2.350 ± 0.099) × 1012 kg   (ΔM/M = 4%, SNR = 23.6) Derived bulk density ρ = (1.95 ± 0.16) g/cm3   (Δρ/ρ = 8%, SNR = 12.5)


References
M61(2006):Ostro, S.J., Margot, J.L., Benner, L.A.M., Giorgini, J.D., Scheeres, D.J., Fahnestock, E.G., Broschart, S.B., Bellerose, J., Nolan, M.C., Magri, C., Pravec, P., Scheirich, P., Rose, R., Jurgens, R.F., De Jong, E.M., Suzuki, S., 2006. Radar Imaging of Binary Near-Earth Asteroid (66391) 1999 KW4. Science 314, 1276–1280.