Dynamics of exoplanets and exosatellites in binaries

Resumo

The study of extrasolar planets is one of the most dynamic fields of astronomical research nowadays. There are many observational programs dedicated to the search of these objects that have already detected more than 3000 planets orbiting stars different from the Sun. There is also the possibility of finding satellites orbiting these planets. Despite the great success, the difficulties for the discovery of these bodies are huge. On one side, the signal of planets and satellites is very weak at the distances they are, often only a bit above the noise level of the instrumentation. On the other side, that signal is easily masked by the one of the star or by the presence of other bodies in the system. All of this leads to the necessity of knowing with high precision the dynamics of this type of systems, in order to design strategies that maximize the chances of detection. It’s a n-body problem, which doesn’t have a general analytical solution, that is why each case must be studied separately. It’s also necessary to take into account the astrophysical peculiarities that may appear in some kind of stars, such as flares, spots, intense magnetic activity, non-spherical shape, etc. Other factors that must be addressed are firstly the habitability of the planets or even of satellites orbiting gas giants. There are studies that calculate the range of distances from the star for the planet to have similar atmospheric and irradiation conditions to the Earth. We also have the stability of the system. In many cases dynamical processes (planetary migrations, Kozai cycles, etc.) may cause instability in the systems, making the planets abandon the habitability zone or even be expelled from the system. Among the numerous possibilities, maybe the most interesting systems dynamically speaking are multiple stars. The presence of other stars has an important influence in the dynamics, the stability, and even in the habitability of the planets and satellites of the system. All in all, this work is about the dynamical study, including the habitability, of planetary systems, with the objective of refining the detection techniques to be able to find Earth-like planets or large satellites orbiting gas giants with similar conditions to our planet.