Summary for : (624) Hektor

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
MBAD-- | --1.53 ± 0.48   (C)31 %230.7 ± 23.410.2 %9.82e+18 ± 6.77e+177 %SEVM
MBAD-- | --1.65 ± 0.55   (C)33 %225.7 ± 17.67.8 %9.94e+18 ± 2.34e+1824 %Sw.avg
MBAX1.63 ± 0.32   (C)20 %226.7 ± 15.26.7 %9.95e+18 ± 1.20e+171 %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
(624) Hektor203.00 (+3.59 / -3.59)1.8 % / 1.8 % NEATM2003D92 59.67 1
(624) Hektor239.19 (+2.40 / -2.40)1.0 % / 1.0 % NEATM2003D9 12.42 2
(624) Hektor230.99 (+3.94 / -3.94)1.7 % / 1.7 % TPM2011D83 0.00 3
(624) Hektor163.89 (+7.19 / -7.19)4.4 % / 4.4 % NEATM2011D7312 86.43 4
(624) Hektor250.00 (+26.00 / -26.00)10.4 % / 10.4 % MDM:LI2014D120 0.55 5
(624) Hektor270.00 (+22.00 / -22.00)8.1 % / 8.1 % MDM:LI2014D120 3.19 6
(624) Hektor256.00 (+12.00 / -12.00)4.7 % / 4.7 % MDM:LI2014D120 4.43 7
(624) Hektor224.00 (+34.00 / -34.00)15.2 % / 15.2 % DYN:S2014D120 0.04 8
(624) Hektor175.00 (+6.00 / -21.00)3.4 % / 12.0 % TPM2015D1182 17.04 9
(624) Hektor181.00 (+1.00 / -10.00)0.6 % / 5.5 % TPM2015D1182 81.76 10
(624) Hektor186.00 (+1.00 / -34.00)0.5 % / 18.3 % TPM2015D1182 6.53 11
(624) Hektor192.40 (+19.24 / -19.24)10.0 % / 10.0 % NEATM2018D119 3.97 12
(624) Hektor233.92 (+23.39 / -23.39)10.0 % / 10.0 % NEATM2018D119 0.02 13
(624) Hektor242.18 (+48.44 / -48.44)20.0 % / 20.0 % NEATM2018D119 0.06 14

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).
3: Values with asymmetric errors are currently just diplayed but disabled (unchecked) for the average calculation.

DYN:S : Dynamically obtained: motion of satellite. MDM:LI : Multi-Data Modeling: Lightcurves + Images (e.g. AO). NEATM : Near-Earth Asteroid Thermal Model. TPM : Thermophysical Model.


EVM diam. average D = (230.7 ± 23.42) km   (ΔD/D = 10%, SNR = 9.85) Derived bulk density ρ = (1.53 ± 0.48) g/cm3   (Δρ/ρ = 31%, SNR = 3.2)


References
D9(2003):Fernández, Y.R., Sheppard, S.S., Jewitt, D.C., 2003. The Albedo Distribution of Jovian Trojan Asteroids. Astronomical Journal 126, 1563–1574.
D73(2011):Grav, T., Mainzer, A.K., Bauer, J., Masiero, J., Spahr, T., McMillan, R.S., Walker, R., Cutri, R., Wright, E., Eisenhardt, P.R.M., Blauvelt, E., DeBaun, E., Elsbury, D., Gautier, IV, T., Gomillion, S., Hand, E., Wilkins, A., 2011. WISE/NEOWISE Observations of the Jovian Trojans: Preliminary Results. Astrophysical Journal 742, 40.
D83(2011):Usui, F., Kuroda, D., Müller, T.G., Hasegawa, S., Ishiguro, M., Ootsubo, T., Ishihara, D., Kataza, H., Takita, S., Oyabu, S., Ueno, M., Matsuhara, H., Onaka, T., 2011. Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey. Publications of the Astronomical Society of Japan 63, 1117–1138.
D118(2015):Hanuš, J., Delbo, M., Ďurech, J., Alí-Lagoa, V., 2015. Thermophysical modeling of asteroids from WISE thermal infrared data – Significance of the shape model and the pole orientation uncertainties. Icarus 256, 101–116. https://doi.org/10.1016/j.icarus.2015.04.014
D119(2018):Alí-Lagoa, V., Müller, T.G., Usui, F., Hasegawa, S., 2018. The AKARI IRC asteroid flux catalogue: updated diameters and albedos. Astronomy and Astrophysics 612, A85. https://doi.org/10.1051/0004-6361/201731806
D120(2014):Marchis, F., Durech, J., Castillo-Rogez, J., Vachier, F., Cuk, M., Berthier, J., Wong, M.H., Kalas, P., Duchene, G., van Dam, M.A., Hamanowa, H., Viikinkoski, M., 2014. The Puzzling Mutual Orbit of the Binary Trojan Asteroid (624) Hektor. The Astrophysical Journal 783, L37. https://doi.org/10.1088/2041-8205/783/2/L37

Mass estimates

DesignationMass / Err (kg)ΔM/MMethodYearRefNχ2Use
(624) Hektor9.95e+18 ± 1.20e+171 %BinImg 2011M1061.22 1
(624) Hektor7.90e+18 ± 1.40e+1818 %BinImg 2014M138 1.88 2
(624) Hektor1.26e+19 ± 6.40e+1851 %Deflec 2023M1390.19 3

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. Deflec : Orbital deflection (close encounter) of one or several test asteroids (classical LSQ).


EVM mass average M = (9.817 ± 0.677) × 1018 kg   (ΔM/M = 7%, SNR = 14.5) Derived bulk density ρ = (1.53 ± 0.48) g/cm3   (Δρ/ρ = 31%, SNR = 3.2)


References
M106(2011):Descamps et al. (pers. com.). See: Carry, B., 2012. Density of asteroids. Planetary and Space Science, Volume 73, Issue 1, p. 98-118.
M138(2014):Marchis, F., et al. (2014): The Puzzling Mutual Orbit of the Binary Trojan Asteroid (624) Hektor. The Astrophysical Journal Letters, Volume 783, Issue 2, article id. L37, 6 pp. (2014). Bibcode: 2014ApJ...783L..37M
M139(2023):Kretlow, M., 2023 : yet unpubl.