Summary for : (87) Sylvia

DynT.TT.BT T.L B T.DDensity (g/cm^3)Δρ/ρDiameter (km)ΔD/DMass (kg)ΔM/MRefAvg.M
MBAPXX | XX1.38 ± 0.45   (C)33 %276.0 ± 14.05.1 %1.52e+19 ± 4.43e+1829 %SEVM
MBAPXX | XX1.40 ± 1.50   (E)108 %272.5 ± 9.63.5 %1.48e+19 ± 1.59e+19107 %Sw.avg
MBAX1.31 ± 0.15   (B)11 %278.1 ± 10.83.9 %1.48e+19 ± 0.00e+000 %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
(87) Sylvia260.94 ± 13.305.1 % STM2004D931 1.29 1
(87) Sylvia286.50 ± 11.504.0 % Img-TE2005D21 0.83 2
(87) Sylvia282.00 ± 3.501.2 % Img2006D34 2.92 3
(87) Sylvia232.16 ± 8.793.8 % STM2010D642 24.89 4
(87) Sylvia290.31 ± 14.465.0 % NEATM2010D64 0.98 5
(87) Sylvia262.67 ± 3.851.5 % STM2011D83 12.02 6
(87) Sylvia288.38 ± 7.612.6 % NEATM2011D72 2.64 7
(87) Sylvia273.00 ± 5.001.8 % ADAM2017D100 0.36 8

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. Img : Apparent size in disk-resolved imaging. Img-TE : Triaxial ellipsoid model from images. NEATM : Near-Earth Asteroid Thermal Model. STM : Standard Thermal Model.



EVM diam. average D = (276.0 ± 14.04) km   (ΔD/D = 5%, SNR = 19.65) Derived bulk density ρ = (1.38 ± 0.45) g/cm3   (Δρ/ρ = 33%, SNR = 3.0)



References
D21(2005):Marchis, F., Descamps, P., Hestroffer, D., Berthier, J., 2005. Discovery of the triple asteroidal system 87 Sylvia. Nature 436, 822–824.
D34(2006):Marchis, F., Kaasalainen, M., Hom, E.F.Y., Berthier, J., Enriquez, J., Hestroffer, D., Le Mignant, D., de Pater, I., 2006. Shape, size and multiplicity of main-belt asteroids. Icarus 185, 39–63.
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.
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
(87) Sylvia5.37e+19 ± 1.99e+1937 %Deflec 1999M18123.73 1
(87) Sylvia1.39e+19 ± 1.99e+1814 %Deflec 2001M28120.46 2
(87) Sylvia1.46e+19 ± 1.00e+187 %BinImg 2001M270.42 3
(87) Sylvia1.48e+19 ± 5.97e+160 %BinImg 2005M4855.43 4
(87) Sylvia3.58e+19 ± 1.79e+1950 %Ephem 2007M62121.32 5
(87) Sylvia5.17e+19 ± 2.19e+1942 %Deflec 2008M78122.77 6
(87) Sylvia1.17e+19 ± 1.29e+19110 %Deflec 2011M97120.08 7
(87) Sylvia1.36e+19 ± 1.09e+1980 %Deflec 2011M97120.02 8
(87) Sylvia1.18e+19 ± 1.06e+1990 %Deflec 2011M97120.11 9
(87) Sylvia5.98e+18 ± 1.88e+19314 %Deflec 2011M97120.24 10
(87) Sylvia2.15e+19 ± 1.99e+189 %OrbFitN 2014M1239.82 11
(87) Sylvia1.83e+19 ± 3.57e+1819 %Ephem 2019M1260.74 12

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).

BinImg : Binary imaged at optical wavelength. 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 = (1.524 ± 0.443) × 1019 kg   (ΔM/M = 29%, SNR = 3.4) Derived bulk density ρ = (1.38 ± 0.45) g/cm3   (Δρ/ρ = 33%, SNR = 3.0)



References
M18(1999):Vasiliev, M.V., Yagudina, E.I., 1999. Determination of masses for 26 selected minor planets from analysis of observations their mutual encounters with asteroids of lesser mass, in: Communications of IAA of RAS.
M27(2001):Margot, J.L., Brown, M.E., 2001. Discovery and characterization of binary asteroids 22 Kalliope and 87 Sylvia, in: AAS/Division for Planetary Sciences Meeting Abstracts
M28(2001):Krasinsky, G.A., Pitjeva, E.V., Vasiliev, M.V., Yagudina, E.I., 2001. Estimating masses of asteroids, in: Communications of IAA of RAS.
M48(2005):Marchis, F., Descamps, P., Hestroffer, D., Berthier, J., 2005. Discovery of the triple asteroidal system 87 Sylvia. Nature 436, 822–824.
M62(2007):Aslan, Z., Gumerov, R., Hudkova, L., Ivantsov, A., Khamitov, I., Pinigin, G., 2007. Mass Determination of Small Solar System Bodies with Ground-based Observations, in: O. Demircan, S. O. Selam, & B. Albayrak (Ed.), Solar and Stellar Physics Through Eclipses, pp. 52–58.
M78(2008):Ivantsov, A., 2008. Asteroid mass determination at Nikolaev Observatory. Planetary and Space Science 56, 1857–1861.
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,