The mass of Himalia from the perturbations on other satellites

Nikolai V. Emelyanov (1, 2, 3)

1 SSIA - Shternberg State Institute of Astronomy
2 IMCCE - Institut de Mécanique Céleste et de Calcul des Ephémérides
3 GAP - Groupe Astrométrie et Planétologie

We made an attempt to determine the masses of two Jupiter's outer satellites, Himalia (J6) and Pasiphae (J8), on the basis of their perturbations on other satellites. For this, all observations available in the database of the Natural Satellite Data Center (NSDC, http://lnfm1.sai.msu.ru/neb/nss/index.htm) were used. New value of the product of Himalia's mass by the gravity constant Gm = (0.28 ± 0.04) km^3/s² was obtained (the uncertainty of one-sigma is given). We demonstrated that the determination of the mass is possible only because of one close approach of Himalia (J6) and Elara (J7) which took place on July 15th, 1949, when the distance between them was 65 031 km. Independent determination of Himalia's mass allowed to obtain the relationship between assumed values of density and geometric albedo of this satellite. Researches based on simulated observations showed that such a determination of the mass for the satellite Pasiphae (J8) is impossible.

Domaines: Astrophysique [astro-ph]

Nikolai V. Emelyanov. The mass of Himalia from the perturbations on other satellites. Astronomy and Astrophysics - A&A, 2005, 438, pp.L33-L36. ⟨10.1051/0004-6361:200500143⟩. ⟨hal-03742251⟩