Search Publications
Dynamics of two satellites in the 2/1 Mean–Motion resonance: application to the case of Enceladus and Dione
Yokoyama, T.; Callegari, N.
The dynamics of a pair of satellites similar to Enceladus–Dione is investigated with a two-degrees-of-freedom model written in the domain of the planar general three-body problem. Using surfaces of section and spectral analysis methods, we study the phase space of the system in terms of several parameters, including the most recent data. A detaile…
Strands and braids in narrow planetary rings: a scattering system approach
Merlo, Olivier; Benet, Luis
We address the occurrence of narrow planetary rings and some of their structural properties, in particular when the rings are shepherded. We consider the problem as Hamiltonian scattering of a large number of non-interacting massless point particles in an effective potential. Using the existence of stable motion in scattering regions in this set u…
The use of radar observations of Near-Earth Asteroids in the determination of the dynamical equinox
Yagudina, Eleonora I.
Near-Earth Asteroids (NEAs) are Solar system special class objects attracting the attention of astronomical community especially during several of the last decades. To some extent the NEAs have an advantage over the minor planets of the main belt: due to close and regular approaches to the Earth the radar observations of NEAs can be obtained for t…
Earth Rotation in the Hipparcos Reference Frame
Vondrák, J.; Ron, C.; Pešek, I.
New determination of the Earth orientation parameters (EOP), based on optical astrometry observations since the beginning of the century, is now under preparation by the Working group established by Commission 19 of the IAU. The Hipparcos catalog is to define the celestial reference frame in which the new series of EOP are to be described, The nov…
Astrometry in the Future
Seidelmann, P. K.
The introduction of the extragalactic reference frame and the availability of the Hipparcos and Tycho catalogs will have major impacts on changing the accuracy levels of astrometry in the future. There is a need for accurate densification of the reference frames down to at least 20th magnitude, Also accurate space motions and distances …