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RLarsen
2007-Apr-08, 01:46 AM
My understanding (albeit limited) of galaxies is that they are rather flat in shape, much like the solar system is also rather flat, much like systems around planets are flat (i.e., polar orbits are rare).
Can we assume then that there is a galactic ecliptic, and that the ecliptics around the stars within that galaxy are going to be generally in line with this galactic ecliptic?

[-- From this could we assume that planets, wherever they may be, rotate in the same directions and orbit their stars in the same directions?]

01101001
2007-Apr-09, 01:32 AM
My understanding (albeit limited) of galaxies is that they are rather flat in shape[...]

Spirals? (Ellipticals and irregulars are clearly not flat.) Some spirals are. Some aren't.

Our Milky Way probably isn't flat.

APOD: Warped galaxy (http://antwrp.gsfc.nasa.gov/apod/ap030607.html)


The disks of many spirals are thin and flat, but not solid. Spiral disks are loose conglomerations of billions of stars and diffuse gas all gravitationally orbiting a galaxy center. A flat disk is thought to be created by sticky collisions of large gas clouds early in the galaxy's formation. Warped disks are not uncommon, though, and even our own Milky Way Galaxy is thought to have a small warp. The causes of spiral warps are still being investigated, but some warps are thought to result from interactions or even collisions between galaxies.


Can we assume then that there is a galactic ecliptic, and that the ecliptics around the stars within that galaxy are going to be generally in line with this galactic ecliptic?

[-- From this could we assume that planets, wherever they may be, rotate in the same directions and orbit their stars in the same directions?]

No. I've never heard that the arrangment of bodies about a star, condensed from an accretion disk, has any correlation to the structure of the parent galaxy. Our solar system isn't aligned with the Milky Way's equator.

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John Mendenhall
2007-Apr-09, 05:17 PM
(snip)

No. I've never heard that the arrangment of bodies about a star, condensed from an accretion disk, has any correlation to the structure of the parent galaxy. Our solar system isn't aligned with the Milky Way's equator.

(snip)

I agree, I've never heard of any correlation. On the other hand, I've never heard of any research on the question, either.

edit: And I couldn't find any on a quick search.

01101001
2007-Apr-10, 03:46 AM
On the other hand, I've never heard of any research on the question, either.

For instance, should we expect the planes of binary pairs to correlate to the galactic plane?

Abstract: Orientation of the Orbital Planes of Visual Binary Systems (http://adsabs.harvard.edu/abs/2000AcA....50..211G)


The space distribution of orbital poles for 252 visual binaries is analyzed to check a possible tendency towards parallelism. It is confirmed that orbital planes do not show any trend to be parallel to the Galactic plane. No strong evidence is found for a preferential orientation of the orbital planes for subgroups of binaries with similar periods and eccentricities.