Dynamical stability of extra-solar planets

This project is concerned with the long-term stability of planetary systems. The discovery of the first planet orbiting a sun-like star, i.e.\ 51 Pegasi, in October 1995 was certainly one of the most important advances in Astronomy in the last decade. By the end of November 2000 46 extra-solar planetary systems are known, which are completely different to our Solar System: the planets have masses in the range 0.16 to 11 Jupiter-masses and the move in orbits with semi-major axes in the range 0.16 to 3.3 AU. Furthermore, more than half of them orbit their host star much closer than Mercury, the innermost planet of our Solar System; and one third of these planets move in high eccentric orbits (e >= 0.3). Our study can be divided into three parts: In the first part the investigations are restricted to the planar problem, which will give a detailed picture of the stability of massive planets (i.e. Jupiter-size planets) moving in the orbital plane of a double star system. A special emphasis is given to the real binaries, where planets have been discovered, i.e. 55 Cnc, tau Boo, Gl86 and 16 CygB. The latter is very interesting because of its high eccentric orbit. Such orbits will be studied in detail in this project. In the second part we will concentrate on the investigation of inclined orbits in the different systems, in order to see how the stable zone varies with the inclination. And in the third part the stability studies will be carried out with different masses of the planet, so that we will have a global picture about the stable zone in double star systems. Especially the extra-solar system, where the planets move in high eccentric orbits will be studied to determine the zones where other planets could exist. The realization of this project will therefore be an essential contribution from the dynamical point of view to the actual research of extra solar-planets.