Summary for : (74) Galatea

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
MBACC- | --1.09 ± 0.92   (D)84 %117.8 ± 11.39.6 %9.34e+17 ± 7.41e+1779 %SEVM
MBACC- | --1.04 ± 2.79   (E)268 %114.7 ± 6.75.9 %8.22e+17 ± 2.20e+18267 %Sw.avg
MBAC6.66 ± 5.94   (D)89 %120.7 ± 7.25.9 %6.13e+18 ± 5.36e+1887 %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
(74) Galatea118.70 ± 2.792.4 % STM2004D93 0.11 1
(74) Galatea127.67 ± 3.342.6 % STM2010D64 8.79 2
(74) Galatea132.02 ± 5.324.0 % NEATM2010D64 7.18 3
(74) Galatea97.83 ± 2.943.0 % Occ2011D9512 46.00 4
(74) Galatea113.08 ± 2.151.9 % STM2011D83 4.76 5

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. Occ : Stellar occultation. STM : Standard Thermal Model.


EVM diam. average D = (117.8 ± 11.28) km   (ΔD/D = 10%, SNR = 10.44) Derived bulk density ρ = (1.09 ± 0.92) g/cm3   (Δρ/ρ = 84%, SNR = 1.2)


References
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.
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.
D95(2011):Dunham, D.W., Herald, D., Frappa, E., Hayamizu, T., Talbot, J., Timerson, B., 2011. Asteroid Occultations. NASA Planetary Data System. EAR-A-3-RDR-OCCULTATIONS-V9.0.

Mass estimates

DesignationMass / Err (kg)ΔM/MMethodYearRefNχ2Use
(74) Galatea6.13e+18 ± 5.36e+1887 %Ephem 2010M930.94 1
(74) Galatea9.94e+17 ± 3.98e+1740 %OrbFitN 2014M1230.02 2
(74) Galatea6.85e+17 ± 3.29e+1748 %Ephem 2019M1260.57 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).

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


EVM mass average M = (9.337 ± 7.407) × 1017 kg   (ΔM/M = 79%, SNR = 1.3) Derived bulk density ρ = (1.09 ± 0.92) g/cm3   (Δρ/ρ = 84%, SNR = 1.2)


References
M93(2010):Fienga, A., Manche, H., Kuchynka, P., Laskar, J., Gastineau, M., 2010. INPOP10a. Scientific Notes.
M123(2014):Goffin, E., 2014. Astrometric asteroid masses: a simultaneous determination. Astronomy & Astrophysics, Volume 565, id.A56, 8 pp.
M126(2019):Fienga, A., et. al, 2019. INPOP19a planetary ephemeris. Notes Scientifiques et Techniques de l'Institut de mécanique céleste,