Summary for : (516) Amherstia

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
MBAMX- | --2.35 ± 1.71   (D)73 %72.2 ± 4.76.5 %4.63e+17 ± 3.25e+1770 %SEVM
MBAMX- | --2.23 ± 4.54   (E)204 %68.2 ± 4.87.1 %3.70e+17 ± 7.50e+17203 %Sw.avg
MBAX8.01 ± 7.60   (D)95 %69.8 ± 4.46.3 %1.43e+18 ± 1.33e+1893 %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
(516) Amherstia73.09 ± 1.702.3 % STM2004D93 0.27 1
(516) Amherstia76.87 ± 2.333.0 % STM2010D64 4.01 2
(516) Amherstia83.09 ± 4.395.3 % NEATM2010D64 6.15 3
(516) Amherstia66.26 ± 0.620.9 % STM2011D832 91.96 4
(516) Amherstia74.27 ± 2.493.4 % NEATM2011D72 0.69 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. STM : Standard Thermal Model.


EVM diam. average D = (72.2 ± 4.73) km   (ΔD/D = 7%, SNR = 15.27) Derived bulk density ρ = (2.35 ± 1.71) g/cm3   (Δρ/ρ = 73%, SNR = 1.4)


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.
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
(516) Amherstia1.43e+18 ± 1.33e+1893 %Ephem 2010M930.53 1
(516) Amherstia3.54e+17 ± 1.63e+1746 %Ephem 2019M1260.45 2

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.


EVM mass average M = (4.626 ± 3.246) × 1017 kg   (ΔM/M = 70%, SNR = 1.4) Derived bulk density ρ = (2.35 ± 1.71) g/cm3   (Δρ/ρ = 73%, SNR = 1.4)


References
M93(2010):Fienga, A., Manche, H., Kuchynka, P., Laskar, J., Gastineau, M., 2010. INPOP10a. Scientific Notes.
M126(2019):Fienga, A., et. al, 2019. INPOP19a planetary ephemeris. Notes Scientifiques et Techniques de l'Institut de mécanique céleste,