Summary for : (121) Hermione

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
MBACCh- | --1.38 ± 0.46   (C)33 %193.1 ± 17.89.2 %5.19e+18 ± 9.54e+1718 %SEVM
MBACCh- | --1.28 ± 0.34   (C)27 %192.2 ± 11.76.1 %4.76e+18 ± 9.28e+1720 %Sw.avg
MBACh1.27 ± 0.22   (B)17 %195.4 ± 10.65.4 %4.97e+18 ± 3.30e+177 %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)

Object is a Gaia target for mass determination !

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
(121) Hermione209.00 ± 4.692.2 % STM2004D932 11.43 1
(121) Hermione178.89 ± 7.194.0 % Img2005D19 3.93 2
(121) Hermione138.80 ± 11.898.6 % Img2005D1912 20.89 3
(121) Hermione189.00 ± 7.003.7 % Img2006D34 0.35 4
(121) Hermione187.00 ± 6.003.2 % KOALA2009D55 1.05 5
(121) Hermione221.56 ± 5.972.7 % STM2010D642 22.66 6
(121) Hermione212.01 ± 7.713.6 % NEATM2010D642 5.99 7
(121) Hermione194.11 ± 2.691.4 % STM2011D832 0.13 8
(121) Hermione164.97 ± 4.512.7 % NEATM2011D7212 39.02 9

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).

Img : Apparent size in disk-resolved imaging. KOALA : Combined lightcurve(s) + occultation(s) + disk-resolved image(s). NEATM : Near-Earth Asteroid Thermal Model. STM : Standard Thermal Model.


EVM diam. average D = (193.1 ± 17.78) km   (ΔD/D = 9%, SNR = 10.86) Derived bulk density ρ = (1.38 ± 0.46) g/cm3   (Δρ/ρ = 33%, SNR = 3.0)


References
D19(2005):Marchis, F., Hestroffer, D., Descamps, P., Berthier, J., Laver, C., de Pater, I., 2005. Mass and density of Asteroid 121 Hermione from an analysis of its companion orbit. Icarus 178, 450–464.
D34(2006):Marchis, F., Kaasalainen, M., Hom, E.F.Y., Berthier, J., Enriquez, J., Hestroffer, D., Le Mignant, D., de Pater, I., 2006. Shape, size and multiplicity of main-belt asteroids. Icarus 185, 39–63.
D55(2009):Descamps, P., Marchis, F., Durech, J., Emery, J.P., Harris, A.W., Kaasalainen, M., Berthier, J., Teng-Chuen-Yu, J.P., Peyrot, A., Hutton, L., Greene, J., Pollock, J., Assafin, M., Vieira-Martins, R., Camargo, J.I.B., Braga-Ribas, F., Vachier, F., Reichart, D.E., Ivarsen, K.M., Crain, J.A., Nysewander, M.C., Lacluyze, A.P., Haislip, J.B., Behrend, R., Colas, F., Lecacheux, J., Bernasconi, L., Roy, R., Baudouin, P., Brunetto, L., Sposetti, S., Manzini, F., 2009. New insights on the binary Asteroid 121 Hermione. Icarus 203, 88–101.
D64(2010):Ryan, E.L., Woodward, C.E., 2010. Rectified Asteroid Albedos and Diameters from IRAS and MSX Photometry Catalogs. Astronomical Journal 140, 933–943.
D72(2011):Masiero, J.R., Mainzer, A.K., Grav, T., Bauer, J.M., Cutri, R.M., Dailey, J., Eisenhardt, P.R.M., McMillan, R.S., Spahr, T.B., Skrutskie, M.F., Tholen, D., Walker, R.G., Wright, E.L., DeBaun, E., Elsbury, D., Gautier, IV, T., Gomillion, S., Wilkins, A., 2011. Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters. Astrophysical Journal 741, 68.
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.
D93(2004):Tedesco, E.F., Noah, P.V., Noah, M.C., Price, S.D., 2004. IRAS Minor Planet Survey. NASA Planetary Data System. IRAS-A-FPA-3-RDR-IMPS-V6.0.

Mass estimates

DesignationMass / Err (kg)ΔM/MMethodYearRefNχ2Use
(121) Hermione9.35e+18 ± 1.59e+1817 %Deflec 2000M20126.83 1
(121) Hermione5.38e+18 ± 2.98e+176 %BinImg 2005M470.39 2
(121) Hermione6.56e+18 ± 2.18e+1833 %Deflec 2005M11920.39 3
(121) Hermione4.70e+18 ± 2.00e+174 %BinImg 2009M846.10 4
(121) Hermione5.12e+18 ± 2.22e+1843 %Deflec 2011M97120.00 5
(121) Hermione6.01e+18 ± 1.70e+1828 %Deflec 2011M97120.23 6
(121) Hermione4.58e+18 ± 2.13e+1847 %Deflec 2011M97120.08 7
(121) Hermione6.27e+18 ± 2.28e+1836 %Deflec 2011M97120.22 8
(121) Hermione4.77e+18 ± 7.95e+1717 %Deflec 2014M12220.28 9
(121) Hermione3.18e+18 ± 3.98e+1713 %OrbFitN 2014M123225.55 10
(121) Hermione5.15e+18 ± 1.02e+1820 %Deflec 2017M12520.00 11
(121) Hermione8.37e+18 ± 3.28e+1839 %Deflec 2017M12520.94 12
(121) Hermione5.37e+18 ± 8.97e+1717 %Deflec 2017M125230.04 13
(121) Hermione4.80e+18 ± 1.96e+1841 %Ephem 2019M12620.04 14

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). Ephem : Planetary ephemeris solution. OrbFitN : Simultaneous multi-asteroid astrometric orbit solution (similar to 'Ephem').


EVM mass average M = (5.194 ± 0.954) × 1018 kg   (ΔM/M = 18%, SNR = 5.4) Derived bulk density ρ = (1.38 ± 0.46) g/cm3   (Δρ/ρ = 33%, SNR = 3.0)


References
M20(2000):Viateau, B., 2000. Mass and density of asteroids (16) Psyche and (121) Hermione. Astronomy and Astrophysics 354, 725–731.
M47(2005):Marchis, F., Hestroffer, D., Descamps, P., Berthier, J., Laver, C., de Pater, I., 2005. Mass and density of Asteroid 121 Hermione from an analysis of its companion orbit. Icarus 178, 450–464.
M84(2009):Descamps, P., Marchis, F., Durech, J., Emery, J.P., Harris, A.W., Kaasalainen, M., Berthier, J., Teng-Chuen-Yu, J.P., Peyrot, A., Hutton, L., Greene, J., Pollock, J., Assafin, M., Vieira-Martins, R., Camargo, J.I.B., Braga-Ribas, F., Vachier, F., Reichart, D.E., Ivarsen, K.M., Crain, J.A., Nysewander, M.C., Lacluyze, A.P., Haislip, J.B., Behrend, R., Colas, F., Lecacheux, J., Bernasconi, L., Roy, R., Baudouin, P., Brunetto, L., Sposetti, S., Manzini, F., 2009. New insights on the binary Asteroid 121 Hermione. Icarus 203, 88–101.
M97(2011):Zielenbach, W., 2011. Mass Determination Studies of 104 Large Asteroids. Astronomical Journal 142, 120–128.
M119(2005):Kretlow, M., 2005. https://astro.kretlow.de .
M122(2014):Kretlow, M., 2014. A New Astrometric Mass Estimate for 121 Hermione. The Minor Planet Bulletin (ISSN 1052-8091), Vol. 41, No. 3, pp. 194-195.
M123(2014):Goffin, E., 2014. Astrometric asteroid masses: a simultaneous determination. Astronomy & Astrophysics, Volume 565, id.A56, 8 pp.
M125(2017):Baer, J., Chesley, S.R., 2017. Simultaneous Mass Determination for Gravitationally Coupled Asteroids. The Astronomical Journal, Volume 154, Issue 2, article id. 76, 11 pp.
M126(2019):Fienga, A., et. al, 2019. INPOP19a planetary ephemeris. Notes Scientifiques et Techniques de l'Institut de mécanique céleste,