Pervasive orbital eccentricities dictate the habitability of extrasolar earths.
The long-term habitability of Earth-like planets requires low orbital eccentricities. A secular perturbation from a distant stellar companion is a very important mechanism in exciting planetary eccentricities, as many of the extrasolar planetary systems are associated with stellar companions. Although the orbital evolution of an Earth-like planet in a stellar binary system is well understood, the effect of a binary perturbation on a more realistic system containing additional gas-giant planets has been very little studied. Here, we provide analytic criteria confirmed by a large ensemble of numerical integrations that identify the initial orbital parameters leading to eccentric orbits. We show that an extrasolar earth is likely to experience a broad range of orbital evolution dictated by the location of a gas-giant planet, which necessitates more focused studies on the effect of eccentricity on the potential for life.
Kita
Ryosuke
R
Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA.
Rasio
Frederic
F
Takeda
Genya
G
D055580:Astronomical Phenomena; D055907:Climatic Processes; D019419:Evolution, Planetary; D005118:Extraterrestrial Environment; D018561:Space Simulation / Q000379:methods; D055609:Stars, Celestial; D013995:Time; D014867:Water
D014867:Water