Summary for : (135) Hertha

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
MBAMXk- | --4.76 ± 1.05   (C)22 %77.1 ± 3.74.8 %1.14e+18 ± 1.88e+1716 %SEVM
MBAMXk- | --5.33 ± 2.12   (C)40 %74.5 ± 3.54.6 %1.15e+18 ± 4.29e+1737 %Sw.avg
MBAXk5.23 ± 0.96   (B)18 %76.1 ± 3.34.3 %1.21e+18 ± 1.60e+1713 %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
(135) Hertha79.23 ± 2.002.5 % STM2004D93 1.17 1
(135) Hertha82.01 ± 3.864.7 % STM2004D94 1.64 2
(135) Hertha67.29 ± 1.892.8 % STM2010D642 26.74 3
(135) Hertha73.77 ± 3.364.6 % STM2010D64 0.96 4
(135) Hertha92.13 ± 5.556.0 % NEATM2010D642 7.37 5
(135) Hertha76.92 ± 3.875.0 % NEATM2010D64 0.00 6
(135) Hertha77.58 ± 2.693.5 % Occ2011D95 0.04 7
(135) Hertha77.00 ± 7.009.1 % MDM:LO2011D78 0.00 8
(135) Hertha72.77 ± 0.871.2 % STM2011D832 24.34 9
(135) Hertha77.00 ± 7.8210.2 % NEATM2011D72 0.00 10
(135) Hertha80.00 ± 2.002.5 % ADAM2017D100 2.16 11

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).

ADAM : All-Data Asteroid Modeling. MDM:LO : Multi-Data Modeling: Lightcurves + Occultations. NEATM : Near-Earth Asteroid Thermal Model. Occ : Stellar occultation. STM : Standard Thermal Model.


EVM diam. average D = (77.1 ± 3.73) km   (ΔD/D = 5%, SNR = 20.64) Derived bulk density ρ = (4.76 ± 1.05) g/cm3   (Δρ/ρ = 22%, SNR = 4.6)


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.
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.
D100(2017):Hanuš, J., Viikinkoski, M., Marchis, F., et al., 2017. Volumes and bulk densities of forty asteroids from ADAM shape modeling. Astronomy and Astrophysics 601, A114 (2017). DOI: 10.1051/0004-6361/201629956

Mass estimates

DesignationMass / Err (kg)ΔM/MMethodYearRefNχ2Use
(135) Hertha1.17e+18 ± 1.17e+1710 %Ephem 2009M860.06 1
(135) Hertha1.82e+18 ± 1.76e+1897 %Ephem 2010M9320.15 2
(135) Hertha9.18e+17 ± 4.03e+1744 %Ephem 2019M1260.30 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.


EVM mass average M = (1.141 ± 0.188) × 1018 kg   (ΔM/M = 16%, SNR = 6.1) Derived bulk density ρ = (4.76 ± 1.05) g/cm3   (Δρ/ρ = 22%, SNR = 4.6)


References
M86(2009):Folkner, W.M., Williams, J.G., Boggs, D.H., 2009. The planetary and lunar ephemeris de 421. IPN Progress Report 42, 1–34.
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,