Summary for : (68) Leto

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
MBAS-S | S-5.64 ± 3.18   (D)56 %100.4 ± 12.012.0 %2.99e+18 ± 1.29e+1843 %SEVM
MBAS-S | S-7.51 ± 4.34   (D)58 %96.4 ± 13.013.5 %3.53e+18 ± 1.45e+1841 %Sw.avg
MBAS3.21 ± 1.92   (D)60 %125.0 ± 6.45.1 %3.28e+18 ± 1.90e+1858 %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
(68) Leto116.33 ± 4.824.1 % STM2004D94 10.91 1
(68) Leto122.56 ± 5.304.3 % STM2004D93 17.47 2
(68) Leto128.06 ± 4.043.2 % STM2010D64 46.85 3
(68) Leto89.75 ± 0.040.0 % STM2010D642 70993.57 4
(68) Leto130.91 ± 6.334.8 % NEATM2010D64 23.22 5
(68) Leto106.84 ± 0.050.0 % NEATM2010D642 16549.04 6
(68) Leto148.00 ± 25.0016.9 % MDM:LO2011D782 3.62 7
(68) Leto151.00 ± 25.0016.6 % MDM:LO2011D782 4.10 8
(68) Leto121.95 ± 1.191.0 % STM2011D832 327.71 9
(68) Leto128.85 ± 4.173.2 % NEATM2011D72 46.52 10

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).

MDM:LO : Multi-Data Modeling: Lightcurves + Occultations. NEATM : Near-Earth Asteroid Thermal Model. STM : Standard Thermal Model.


EVM diam. average D = (100.4 ± 12.04) km   (ΔD/D = 12%, SNR = 8.34) Derived bulk density ρ = (5.64 ± 3.18) g/cm3   (Δρ/ρ = 56%, SNR = 1.8)


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.
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.
D78(2011):Ďurech, J., Kaasalainen, M., Herald, D., Dunham, D., Timerson, B., Hanuš, J., Frappa, E., Talbot, J., Hayamizu, T., Warner, B.D., Pilcher, F., Galád, A., 2011. Combining asteroid models derived by lightcurve inversion with asteroidal occultation silhouettes. Icarus 214, 652–670.
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.
D94(2004):Tedesco, E.F., Egan, M.P., Price, S.D., 2004. MSX Infrared Minor Planet Survey. NASA Planetary Data System. MSX-A-SPIRIT3-5-SBN0003-MIMPS-V1.0.

Mass estimates

DesignationMass / Err (kg)ΔM/MMethodYearRefNχ2Use
(68) Leto1.39e+18 ± 4.00e+18288 %Deflec 2011M970.16 1
(68) Leto2.60e+18 ± 2.75e+18106 %Deflec 2011M970.02 2
(68) Leto3.03e+18 ± 2.73e+1890 %Deflec 2011M970.00 3
(68) Leto7.23e+18 ± 4.85e+1867 %Deflec 2011M9720.76 4
(68) Leto4.18e+18 ± 5.97e+1714 %OrbFitN 2014M1233.93 5
(68) Leto2.16e+18 ± 9.09e+1742 %Ephem 2019M1260.84 6

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 = (2.992 ± 1.295) × 1018 kg   (ΔM/M = 43%, SNR = 2.3) Derived bulk density ρ = (5.64 ± 3.18) g/cm3   (Δρ/ρ = 56%, SNR = 1.8)


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,