Planets in habitable zones: A study of the binary Gamma Cephei

Autor(en)

Rudolf Dvorak, Elke Pilat-Lohinger, Barbara Funk, Florian Freistetter

Abstrakt

The recently discovered planetary system in the binary ? Cep was studied concerning its dynamical evolution. We confirm that the orbital parameters found by the observers are in a stable configuration. The primary aim of this study was to find stable planetary orbits in a habitable region in this system, which consists of a double star (a = 21.36 AU) and a relatively close (a = 2.15 AU) massive (1.7 mjup sin i) planet. We did straightforward numerical integrations of the equations of motion in different dynamical models and determined the stability regions for a fictitious massless planet in the interval of the semimajor axis 0.5 AU <a <1.85 AU around the more massive primary. To confirm the results we used the Fast Lyapunov Indicators (FLI) in separate computations, which are a common tool for determining the chaoticity of an orbit. Both results are in good agreement and unveiled a small island of stable motions close to 1 AU up to an inclination of about 15° (which corresponds to the 3:1 mean motion resonance between the two planets). Additionally we computed the orbits of earthlike planets (up to 90 earthmasses) in the small stable island and found out, that there exists a small window of stable orbits on the inner edge of the habitable zone in ? Cep even for massive planets.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Friedrich-Schiller-Universität Jena

Journal

Astronomy & Astrophysics

Band

398

ISSN

0004-6361

Publikationsdatum

2003

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/planets-in-habitable-zones-a-study-of-the-binary-gamma-cephei(95eb7f90-2130-452c-a0e5-0328d591d0d6).html