Greg D. Moore \(Strider\) wrote:
"I_am_on_Saturn" wrote:

Is Sun positioned at the center of the elliptical orbits of all the
planets?

Keep in mind an ellipse has two "centers" positioned along the semi-major
axis.

The sun is at ONE of these centers.

Thanks for putting "centers" in quotes. What Strider is referring to
are the *foci* of the ellipse. They are removed from the actual *center*
by a distance equal to one half of the major axis' length times the
eccentricity of the ellipse. For an ellipse that happens to be a perfect
circle, the foci and the center are the same point.
(The "eccentricity" is a measure of the "flatness" of the ellipse.
For ellipses, the eccentricity is a number between zero and one. The
larger the number, the more "squashed" the ellipse. An eccentricity of
zero gives a circle.)
--
-- With Best Regards,
Matthew Funke )