ИСТИНА

The paper presents the results of investigation of dynamical behaviour of extrasolar planets with high inclination and large eccentricity orbits. Their motion was considered in the frame of the general three-body problem, i.e. a planet in the close binary system revolving around one of the components. The distance between the star components is much more longer than between the orbiting star and the planet. In the differential equations with regards to the eccentricity and argument of perigee we used the Hamiltonian without the short-periodic terms, excluded by von Zeipel's method to the second order. The differential equations have the equilibrium solutions. The investigation of these solutions allows to draw conclusions about the stability of the motion. The orbits of extrasolar planets with high inclinations and large eccentricities have been analysed in details. The results indicate that the motion of such orbital system can be stable only in the case when the mutual inclination of the orbits is within a defined interval. When the angle of the mutual inclination is out of this range the motion is unstable. In this case the eccentricity of a planet increases and after some time in the perigee the large tidal forces will destroy a planet. As an example the binary system 61 Cygni was considered. The theoretical results were verified by the numerical integration.