04/30/02
ROZELOT Jean-Pierre	OCA/CERGA
Av. Copernic	PNST-
06130	GRASSE, F

Presentation 1 : Oral
Accurate determination of the solar successive gravitational moments: Astrophysical interest.
Rozelot J.P & Lefebvre S.
From all the fundamental parameters of the Sun (diameter, mass, effective temperature, etc), the successive gravitational moments that determine the inertia moments of the body, are still very poorly known. However, at the first order (l= 2), the quadrupole moment operates in many astrophysical applications: accurate determination of the planetary orbits, relativistic contribution of the lines of apsides (particularly still uncertain), residual relativistic precession of minor planets, accurate determination of the parameters in the post newtonian formalism, etc... Moreover, the successive gravitational moments have a physical meaning: they tell us how much the Sun's material contents deviate from a purely spherical distribution. And thus, their precise determination gives indications on the internal structure of the Sun. In this presentation, we will explain why it is difficult to compute these parameters, how we can give the best values and how they will be determined in a near future by space experiments.

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