Summary for : (212) Medea

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
MBADCX:-- | --1.98 ± 2.37   (E)120 %144.1 ± 6.84.7 %3.11e+18 ± 3.69e+18119 %SEVM
MBADCX:-- | --1.48 ± 3.60   (E)243 %143.6 ± 4.33.0 %2.30e+18 ± 5.58e+18243 %Sw.avg
MBAD8.41 ± 1.43   (X)17 %144.1 ± 7.25.0 %1.32e+19 ± 1.00e+188 %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
(212) Medea136.11 ± 2.501.8 % STM2004D93 10.29 1
(212) Medea142.56 ± 4.002.8 % STM2010D64 0.15 2
(212) Medea146.24 ± 7.915.4 % NEATM2010D64 0.07 3
(212) Medea153.72 ± 2.881.9 % STM2011D83 11.09 4

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 = (144.1 ± 6.80) km   (ΔD/D = 5%, SNR = 21.18) Derived bulk density ρ = (1.98 ± 2.37) g/cm3   (Δρ/ρ = 120%, SNR = 0.8)


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.

Mass estimates

DesignationMass / Err (kg)ΔM/MMethodYearRefNχ2Use
(212) Medea1.32e+19 ± 1.05e+188 %Ephem 2010M93292.41 1
(212) Medea2.19e+18 ± 1.99e+179 %OrbFitN 2014M12321.35 2
(212) Medea8.98e+17 ± 4.45e+1750 %Ephem 2019M12624.62 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 = (3.106 ± 3.687) × 1018 kg   (ΔM/M = 119%, SNR = 0.8) Derived bulk density ρ = (1.98 ± 2.37) g/cm3   (Δρ/ρ = 120%, SNR = 0.8)


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,