Stability of planetary orbits in binary systems

¹ Institut für Theoretische Astrophysik, Universität Heidelberg, Albert Überle Straße 2, 69120 Heidelberg, Germany
² Department of Physics, University of Texas at Arlington, Arlington, TX 76019-0059, USA e-mail: [zmusielak;cuntz;emarshall]@uta.edu
³ Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL 35899, USA

Received: 10 February 2004
Accepted: 23 December 2004

Abstract

Stability of S-type and P-type planetary orbits in binary systems of different mass and separation ratios is investigated. Criteria for stable, marginally stable and unstable planetary orbits are specified. These criteria are used to determine regions of stability of planetary orbits in different binary systems with Jupiter-type planets. The obtained results show that the regions of stability for S-type orbits depend on the distance ratio between the star and planet, and the stellar companions, in the range of 0.22 and 0.46, depending on the mass ratio. For P-type orbits, the regions of stability also depend on that distance ratio, in the range of 1.75 and 2.45, again depending on the the mass ratio. Applications of these results to three observed binary systems with giant planets, namely, τ Boo, HD 195019 and GJ 86, show that the orbits of the giant planets in those systems can be classified as stable, as expected.