Masses and densities of minor planets

Yu. Chernetenko, O. Kochetova, and V. Shor

Institute of Applied Astronomy of RAS, St. Petersburg, Russia

last updated 04 July 2006

In the Table below the masses of some asteroids which were determined during the last years are listed. They were found from perturbations which they produced in the motion of some other asteroids — test bodies. The listed values were determined from observations of many test bodies by the weighted least square fit for one perturbing mass and corrections to the orbit elements of all used test bodies. Beforehand, the sought-for mass was estimated from observations of each individual test body taken separately, and all the bodies with the value of standard error of mass determination less than certain quantity were included in subsequent general solution. Also these runs were used for estimation of standard error of observations of each asteroid — test body.

Table contains following columns: the asteroid number and name, its mass, the number of test bodies used in general solution, and the total number of observations used in it. The last three columns contain: the diameter used for calculation of the volume density, the resulted value for density and the taxonomic class of asteroid for comparison.

For the mass of 15 Eunomia we give two values:

  1. based on the observations of asteroid 50278 in accordance with paper (in print): A.Vitagliano and R.M.Stoss “New mass determination of (15) Eunomia based on a very close encounter with (50278) 2000 CZ12”;

  2. based on the observations of 98 asteroids (including 50278) with the values of standard error of mass determination less than 3.0 10-11 MSun.

For three binary asteroids in our list (22 Kalliope, 45 Eugenia and 121 Hermione) the masses and densities based on analyses of motion of their satellites are given in footnotes (see http://www.johnstonsarchive.net/astro/asteroidmoons, updated 1 September 2005). As the masses at this site are given in kg, they were transformed in the fraction of the Sun mass.

Perturbing asteroid Mass
(10-11 MSun)
Number of
perturbed
asteroids
Number of
observations
IRAS
diameter
(km)
Density
(g/cm3)
Taxonomic
class
3 Juno 0.91 ± 0.20 8750771233.922.7S
4 Vesta 12.84 ±0.09 13760909468.304.8V
6 Hebe 0.69 ± 0.09 3611063185.184.2S
7 Iris 1.20 ± 0.09 394 174050 199.835.7S
9 Metis 0.254 ± 0.057 15252881170*2.0S
10 Hygiea4.06 ± 0.19 373159591407.122.3C
11 Parthenope 0.287 ± 0.008 4618083153.333.0S
15 Eunomiaa) 1.62 ± 0.071 (50278)110255.34 3.7S
15 Eunomiab) 1.58 ± 0.059873770255.34 3.6S
16 Psyche 0.68 ± 0.14215106175253.16 1.6M
17 Thetis 0.033 ± 0.0042825386 90.041.7S
19 Fortuna 0.47 ± 0.045037070200* 2.2G
22 Kalliope 0.85 ± 0.281)3210887181.00 5.5M
24 Themis 0.35 ± 0.087738303198* 1.7C
29 Amphitrite 0.77 ± 0.13154596212.22 3.1S
31 Euphrosyne 0.85 ± 0.321813729255.90 1.9C
45 Eugenia 0.30 ± 0.112)9739682214.63 1.2FC
48 Doris 0.61 ± 0.30427733221.81 2.1CG
52 Europa 1.27 ± 0.25268445302.51 1.8CF
54 Alexandra 0.26 ± 0.0713 7221165.75 2.2C
65 Cybele 0.58 ± 0.15258689237.26 1.6P
88 Thisbe 0.59 ± 0.126425124200.57 2.8CF
92 Undina 0.26 ± 0.1665028126.42 4.9M
121 Hermione 0.45 ± 0.05 3,4)124389208.99 1.9C
324 Bamberga 0.53 ± 0.2310876013229.43 1.7CP
444 Gyptis 0.45 ± 0.108950098159.57 4.2C
451 Patientia 0.59 ± 0.29269862224.96 2.0CU
511 Davida 2.29 ± 0.2010252213326.07 2.5C
532 Herculina 1.15 ± 0.22188100740222.19 4.0S
704 Interamnia 1.27 ± 0.303218155316.62 1.5F
* - diameters from DE405, E.M.Standish, 1998

1) Mass22: 0.368 x 10-11 MSun;
    Density: 2.03 ± 0.16 g/cm3
Margot, J.L. & Brown, M.E. 2003, A Low-Density M-type Asteroid in the Main Belt, Science, 300:1939–1942.
2) Mass45: 0.29 x 10-11 MSun;
    Density: 1.12 ± 0.3 g/cm3
Marchis, F., J. Berthier, P. Descamps, D. Hestroffer, F. Vachier, C. Clergeon, and I. de Pater, 2005, "45 Eugenia and Petit-Prince", Univ. of California-Berkeley Astronomy Dept.
3) Mass121: 0.74 x 10-11 MSun;
    Density: 3.1 ± 0.8 g/cm3
Marchis, F., Descamps, P., Berthier, J., Hestroffer, D., de Pater, I., Conrad, A., Le Mignard, D., Chaffee, F., & Gavel, D. 2003, Searching and Studying Binary Asteroids with AO Systems, AAS/Division for Planetary Sciences Meeting #35, #24.03.
4) Mass121: 0.27 x 10-11 MSun;
    Density: 1.1 ± 0.3 g/cm3
Marchis, F., J. Berthier, P. Descamps, D. Hestroffer, F. Vachier, C. Clergeon, and I. de Pater, 2005, "121 Hermione and S/2002(121)", Univ. of California-Berkeley Astronomy Dept.

More details can be found in the papers:

  1. Kochetova O., Chernetenko Yu. Determination of mass of Jupiter and that of some minor planets from observations of minor planets moving in 2:1 commensurability with Jupiter. Dynamics of Natural and Artificial Celestial Bodies Eds. Pretka-Ziomek H., Wnuk E., Seidelmann P.K., Richardson P. Dordrecht; Kluwer Acad. Publ. 2001, 333–334.

  2. Chernetenko Yu., Kochetova O. Masses of some large minor planets. In: Asteroids, Comets, Meteors. 2002, Berlin, 437–440.

  3. Kochetova O. Determination of large asteroid masses by the dynamical method. Solar System Research, 38, No 1, 2004, 66–75.

To contact with authors:

Yu.A. Chernetenkocya@ipa.nw.ru
O.M. Kochetovakom@ipa.nw.ru
V.A. Shorshor@ipa.nw.ru



2005. Designed by N.Zheleznov