NAMOUNI , Fathi

Solar system Centaurs originate in transneptunian space from where planet orbit crossing events inject their orbits inside the giant planets' domain. Here, we examine this injection process in the three-body problem by studying the orbital evolution of transneptunian asteroids located at Neptune's collision singularity as a function of the...

Jet systems with two unequal components interact with their parent accretion disks through the asymmetric removal of linear momentum from the star-disk system. We show that as a result of this interaction, the disk's state of least energy is not made up of orbits that lie in a plane containing the star's equator, as in a disk without jets. The...

Half the known extrasolar planets have orbital eccentricities in excess of 0.3. Such large eccentricities are surprising as it is thought that planets form in a protoplanetary disk on nearly circular orbits much like the current states of the solar system planets. Possible explanations for the large planetary eccentricities include the...

We develop a phenomenological theory that aims to account for the origin of the large eccentricities of extrasolar planets and that of the small eccentricities in the solar system, the preference for apsidal alignment in nonresonant multiplanet systems, and the origin of the similarities in the eccentricity distribution of extrasolar planets...

International audience

International audience

International audience

International audience

International audience

The accelerated Kepler problem is obtained by adding a constant acceleration to the classical two-body Kepler problem. This setting models the dynamics of a jet-sustaining accretion disk and its content of forming planets as the disk loses linear momentum through the asymmetric jet-counterjet system it powers. The dynamics of the accelerated...

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We study the influence of mutual planetary perturbations on the process of eccentricity excitation by jet acceleration suggested by Namouni (Astron. J. 130, 280 294). Modeling the jet's action by a constant-direction acceleration, we solve the linear secular equations of the combined planetary perturbations and the jet acceleration of the host...

International audience