Summary for : (790) Pretoria

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
MBAP-X | X-2.41 ± 1.13   (C)47 %162.8 ± 10.56.5 %5.44e+18 ± 2.32e+1843 %SEVM
MBAP-X | X-2.93 ± 0.90   (C)31 %160.5 ± 7.24.5 %6.33e+18 ± 1.75e+1828 %Sw.avg
MBAX2.09 ± 0.45   (C)22 %161.0 ± 11.26.9 %4.58e+18 ± 2.80e+176 %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
(790) Pretoria170.36 ± 2.591.5 % STM2004D93 8.61 1
(790) Pretoria165.45 ± 9.335.6 % STM2010D64 0.08 2
(790) Pretoria173.41 ± 7.384.3 % NEATM2010D64 2.08 3
(790) Pretoria151.47 ± 2.821.9 % Occ2011D952 16.03 4
(790) Pretoria144.85 ± 4.943.4 % STM2011D832 13.14 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 = (162.8 ± 10.54) km   (ΔD/D = 6%, SNR = 15.44) Derived bulk density ρ = (2.41 ± 1.13) g/cm3   (Δρ/ρ = 47%, SNR = 2.1)


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
(790) Pretoria4.86e+18 ± 4.76e+1898 %Deflec 2011M970.01 1
(790) Pretoria4.30e+18 ± 4.73e+18110 %Deflec 2011M970.06 2
(790) Pretoria9.74e+18 ± 1.79e+1818 %OrbFitN 2014M1235.79 3
(790) Pretoria3.61e+18 ± 1.73e+1848 %Ephem 2019M1261.12 4

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).

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 = (5.439 ± 2.323) × 1018 kg   (ΔM/M = 43%, SNR = 2.3) Derived bulk density ρ = (2.41 ± 1.13) g/cm3   (Δρ/ρ = 47%, SNR = 2.1)


References
M97(2011):Zielenbach, W., 2011. Mass Determination Studies of 104 Large Asteroids. Astronomical Journal 142, 120–128.
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,