Zusammenfassung
Context. Among the main effects that the Milky Way exerts in binary systems,
the Galactic tide is the only one that is not probabilistic and can be deduced
from a potential. Therefore, it is possible to perform an analysis of the
global structure of the phase space of binary systems in the solar
neighbourhood using the Galactic potential. Aims. The aim of this work is to
obtain a simple model to study the collisionless dynamical evolution of generic
wide binaries systems in the solar neighbourhood. Methods. Through an averaging
process, we reduced the three-dimensional potential of the Galaxy to a secular
one-degree of freedom model. The accuracy of this model was tested by comparing
its predictions with numerical simulations of the exact equations of motion of
a two-body problem disturbed by the Galaxy. Results. Using the one-degree of
freedom model, we developed a detailed dynamical study, finding that the
secular Galactic tide period changes as a function of the separation of the
pair, which also gives a dynamical explanation for the arbitrary classification
between "wide" and "tight" binaries. Moreover, the secular phase space for a
generic gravitationally bound pair is similar to the dynamical structure of a
Lidov-Kozai resonance, but surprisingly this structure is independent of the
masses and semimajor axis of the binary system. Thus, the Galactic potential is
able to excite the initially circular orbit of binary systems to high values of
eccentricity, which has important implications for studies of binary star
systems (with and without exoplanets), comets, and Oort cloud objects.
Nutzer