Summary for : (42355) Typhon

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
TNO--- | --0.32 ± 0.04   (B)14 %178.9 ± 7.54.2 %9.49e+17 ± 5.20e+165 %SEVM
TNO--- | --0.30 ± 0.03   (B)9 %182.3 ± 4.72.6 %9.49e+17 ± 5.20e+165 %Sw.avg
TNO-0.30 ± 0.03   (B)10 %181.7 ± 5.12.8 %9.49e+17 ± 5.20e+165 %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
(42355) Typhon173.80 ± 16.799.7 % NEATM2008D51 0.09 1
(42355) Typhon175.00 ± 17.009.7 % STM2012D871 0.05 2
(42355) Typhon185.00 ± 7.003.8 % STM2012D87 0.76 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. STM : Standard Thermal Model.


EVM diam. average D = (178.9 ± 7.51) km   (ΔD/D = 4%, SNR = 23.82) Derived bulk density ρ = (0.32 ± 0.04) g/cm3   (Δρ/ρ = 14%, SNR = 7.3)


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.
D87(2012):Santos Sanz, P., Lellouch, E., Fornasier, S., Kiss, C., Pál, A., Müller, T., Vilenius, E., Stansberry, J., Mommert, M., Delsanti, A., Mueller, M., Bönhardt, H., Peixinho, N., Henry, F., Ortiz, J.L., Thirouin, A., Protopapa, S., Duffard, R., Szalai, N., Lim, T., Ejeta, C., Hartogh, P., Harris, A.W., Rengel, M., 2012. TNOs are Cool: A Survey of the Transneptunian Region IV. Size/albedo characterization of 15 scattered disk and detached objects observed with Herschel Space Observatory-PACS. Astronomy & Astrophysics, 541, id.A93, 18 pp.

Mass estimates

DesignationMass / Err (kg)ΔM/MMethodYearRefNχ2Use
(42355) Typhon9.49e+17 ± 5.20e+165 %BinImg 2008M760.00 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 = (9.490 ± 0.520) × 1017 kg   (ΔM/M = 5%, SNR = 18.3) Derived bulk density ρ = (0.32 ± 0.04) g/cm3   (Δρ/ρ = 14%, SNR = 7.3)


References
M76(2008):Grundy, W.M., Noll, K.S., Virtanen, J., Muinonen, K., Kern, S.D., Stephens, D.C., Stansberry, J.A., Levison, H.F., Spencer, J.R., 2008. (42355) Typhon Echidna: Scheduling observations for binary orbit determination. Icarus 197, 260–268.