  Many exoplanets are discovered in binary star systems in internal or in
circumbinary orbits. Whether the planet can be habitable or not depends on the
possibility to maintain liquid water on its surface, and therefore on the
luminosity of its host stars and on the dynamical properties of the planetary
orbit. The trajectory of a planet in a double star system can be determined,
approximating stars and planets with point masses, by solving numerically the
equations of motion of the classical three-body system. In this study, we
analyze a large data set of planetary orbits, made up with high precision long
integration at varying: the mass of the planet, its distance from the primary
star, the mass ratio for the two stars in the binary system, and the
eccentricity of the star motion. To simulate the gravitational dynamics, we use
a 15th order integration scheme (IAS15, available within the REBOUND
framework), that provides an optimal solution for long-term integration. In our
data analysis, we evaluate if an orbit is stable or not and also provide the
statistics of different types of instability: collisions with the primary or
secondary star and planets ejected away from the binary star system. Concerning
the stability, we find a significant number of orbits that are only marginally
stable, according to the classification introduced by Musielak et al. 2005. For
planets of negligible mass, we estimate the critical semi-major axis $a_c$ as a
function of the mass ratio and the eccentricity of the binary, in agreement
with the results of Holman and Wiegert 1999. However, we find that for very
massive planets (Super-Jupiters) the critical semi-major axis decrease in some
cases by a few percent, compared to cases in which the mass of the planet is
negligible.
