The instability of planetary systems in binaries: how the Kozai mechanism leads to strong planet-planet interactions

• In this Letter we consider the evolution of a planetary system around a star inside a wide binary. We simulate numerically the evolution of the planetary orbits for both coplanar and highly inclined systems. We find that the Kozai mechanism operates in the latter case. This produces a highly eccentric outer planet the orbit of which crosses those of some of the inner planets. Strong planet-planet interactions then follow, resulting in the ejection of one or more planets. We note that planetary systems resembling our Solar system, formed around single stars in stellar clusters, may exchange into binaries and thus will be vulnerable to planet stripping. This process will reduce the number of Solar system-like planetary systems, and may produce at least some of the observed extrasolar planets.

Subject headings

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

Keyword

planetary

celestial mechanics

stellar dynamics

general

binaries

systems

Publication and Content Type

art (subject category)

ref (subject category)