On the dynamical stability of planets in double stars
- Author(s)
- Elke Pilat-Lohinger, Rudolf Dvorak, Barbara Funk, Eric Bois, Florian Freistetter
- Abstract
The importance of stability studies of planetary motion in binaries arises from the fact that double and multiple star systems are more numerous than single stars - at least in the solar neighborhood. Another impulse to carry out such dynamical studies was the discovery of planets in binaries, where we distinguish between two types of motion: P-type and S-type orbits. A dynamical stability study of two binary systems (? Cephei and Gliese 86) is shown in this investigation, where we examined the region between the two stars in order to find stable zones where other planets might exist. For the determination of the stable zones we used two chaos indicators (1. the Fast Lyapunov Indicator FLI - and 2. the Mean Exponential Growth factor of Nearby Orbits - MEGNO) and additionally straight-forward numerical computations by applying the Lie integration method. In the general stability study of S-type motion we show the results for a double star with mass-ratio 0.2 which can be applied to the binary ? Cephei. A study of this system shows that the eccentric orbits of the secondary and of the detected planet restrict the stable zone for a fictitious second planet to the region inside the discovered planet. In the semi-major axis,inclination (a,i)-plane we have found a characteristic "chaotic path" due to an increase of the stable zone when increasing the inclination and a remaining stable island around 1 AU. For the second system (Gliese 86) we varied (a) the eccentricity of the secondary, (b) the eccentricity of the detected planet, (c) the eccentricity of a fictitious second planet and (d) the inclination of the fictitious second planet, and show the size of its stable zone, which shrinks from about 6 AU (for ebinary = 0.2 and e planet = 0) to about 1.5 AU (for ebinary= 0.7 and e planet = 0.9).
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Université Bordeaux, Friedrich-Schiller-Universität Jena
- Pages
- 543-548
- No. of pages
- 6
- Publication date
- 2003
- Austrian Fields of Science 2012
- 103003 Astronomy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/on-the-dynamical-stability-of-planets-in-double-stars(8e1fbaf9-3229-4afe-8af1-291f5066684e).html