Dynamical evolution of the Gliese 581 planetary system

Hervé Beust (1) , Xavier Bonfils (1, 2) , Xavier Delfosse (1, 3) , Stephane Udry (2)

1 LAOG - Laboratoire d'Astrophysique de Grenoble
2 ObsGE - Observatoire Astronomique de l'Université de Genève
3 OSUG - Observatoire des Sciences de l'Univers de Grenoble

We address the issue of the dynamical evolution of the Gliese 581 planetary system. It is crucial when considering the planets' habitability because the secular evolution of the orbits may regulate their climate, even in the case where the system is stable. We have numerically integrated the planetary system over 10^8 yrs, starting from the present fitted solution. In all cases, the system appears dynamically stable, even in close to pole-on configurations. Only a limited range of inclinations can be excluded. The climate on the planets is expected to be secularly stable, thus not precluding the development of life. Gl 581 remains the best candidate for a planetary system with planets that potentially bear primitive forms of life.

Mots clés: Planetary systems -- Methods: N-body simulations -- Celestial mechanics -- Stars: Gliese 581 -- Astrobiology -- Stars: low-mass; brown dwarfs

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Astrophysique [astro-ph]

Hervé Beust, Xavier Bonfils, Xavier Delfosse, Stephane Udry. Dynamical evolution of the Gliese 581 planetary system. Astronomy and Astrophysics - A&A, 2007. ⟨hal-00195274⟩