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View Full Version : Planetary Systems within Elliptical Binary Stars?


MrMojo1
Jan12-12, 02:27 PM
I read this article in Nature (http://www.nature.com/nature/journal/vaop/ncurrent/full/nature10768.html) as it describes two circumbinary planets. If it is assumed that most stars have a planet orbiting it and most Binary Star systems are elliptical, then wouldn't the majority of Binary Stars system not have planets due to tidal forces of both stars? I am assuming the orbital path of the stars to be intersecting in a figure "eight" pattern (e.g. the last animation of barycentric coordinates on http://en.wikipedia.org/wiki/Barycentric_coordinates_%28astronomy%29).

Thanks in advance.

Drakkith
Jan12-12, 04:42 PM
I would expect that any planets would have to be well outside the orbital radius of the two binary stars or they would become unstable.

D H
Jan12-12, 04:54 PM
I would expect that any planets would have to be well outside the orbital radius of the two binary stars or they would become unstable.
Well outside or well inside. The cited article is about planets orbiting well beyond the orbits of a pair of stars that orbit one another closely (close binaries). Another stable configuration is a pair of stars that orbit one another by some distance, with planets orbiting closely to one of the stars. In this configuration the other star just acts as a perturbation on the planetary orbits.

Drakkith
Jan12-12, 05:25 PM
True, I guess it depends on the mass of the stars and the details of their orbits.