One of the physical constraints to planetary systems around Alpha Centauri A and B that many papers have pointed out is that the planets would need to orbit in the plane of the A-B Orbit, not the equatorial plane of each star (which presumably are not the same, if they're bothering to mention it). That's something I took into account for years when building my fictional systems inside Celestia and now Space Engine, but there's one thing about this that's been nagging at me.

In Alpha Centauri, and other similar wide binary systems, are their any consequences for orbiting their individual primary in a nearly polar orbit? I'm not talking the consequences of extreme axial tilt of the planets, that may or may not be a factor depending on if the planet formed along that A-B plane. Assume the planets don't have unusual obliquity with regards to their primary and avoid extreme seasonal problems. Would orbiting that way have any significant or interesting effects with regards to the stellar magnetosphere or solar wind? Earth and company orbit basically around the sun's equator. They don't pass near or over the sun's poles.

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    $\begingroup$ How significant do you care about? For example, the sun's magnetic field is oriented to its equator. There was a flurry of papers a few years ago with a lot of really pretty diagrams. If you are in a polar orbit you see a very different solar magnetic field at different parts of the year, and so, different cosmic ray flux. It's probably not important near Earth. It might be important in a galactic neighborhood that had a much higher cosmic ray flux. $\endgroup$
    – puppetsock
    Oct 22, 2020 at 0:41
  • $\begingroup$ I suspected it might be only something like that, but was curious if I was missing anything. $\endgroup$ Oct 22, 2020 at 18:01
  • $\begingroup$ First thing that comes to mind when you mention "polar orbits" is the Kozai mechanism: en.wikipedia.org/wiki/Kozai_mechanism $\endgroup$
    – Harthag
    Jan 12, 2022 at 16:07

1 Answer 1


There are no consequences for orbiting in a nearly polar orbit, as long as the planet is not so close to the star that it experiences extreme tidal forces. There are examples of planets in our own solar system with high obliquities (Venus and Uranus), but they have not been affected by their nearly polar orbits.

The reason why there are no consequences is because the stellar wind and magnetosphere are symmetric about the rotation axis of the star. So, if a planet were to orbit in a nearly polar orbit, it would experience the same stellar wind and magnetosphere as a planet orbiting in a more typical equatorial orbit.

There are, however, some consequences for planets orbiting in a nearly polar orbit around a binary star. In particular, the planet would experience more frequent eclipses of one or both stars. This could have an effect on the climate of the planet, depending on the size and brightness of the stars.


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