Orbits of the Equator of the Sun

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Philosophaie
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Orbits of the Equator of the Sun

Post by Philosophaie » Fri Aug 20, 2010 4:29 pm

Earth orbits about 7 Degrees above the Equator of the Sun. Can we discuss the actual orbit in Keplerian Data around the Sun's Equator and how the orbit relates to the Vernal Equinox.
Last edited by Philosophaie on Fri Aug 20, 2010 4:53 pm, edited 1 time in total.

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Chris Peterson
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Re: Orbits of the Equator of the Sun

Post by Chris Peterson » Fri Aug 20, 2010 4:40 pm

Philosophaie wrote:Earth orbits about 7 Degrees above the Equator of the Sun. Can we discuss the actual orbit in Keplerian Data around the Sun's Equator and how the orbit relates to the Vernal Equinox.
The Earth does not orbit above the Sun's equator. It orbits about the center of the Sun, which means it spends as much time below the solar equator as it does above. The Earth's orbit is inclined about 7° to the equator of the Sun.

I'm not sure what you are asking in regards to the Keplerian orbit or the vernal equinox. The latter is certainly unrelated to the inclination of the Earth's orbit.
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Re: Orbits of the Equator of the Sun

Post by Philosophaie » Fri Aug 20, 2010 5:01 pm

In reguards to the Keplerian Orbit I am concerning with the orbit related to angles not using the Ecliptic but instead the orbit with the angles of the distance from the Sun's Equator. I am really interested how the Vernal Equinox points in a 3D orbit relative to the Sun. I know it points somewhere in Pisces. I just thought it would be interesting.

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neufer
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Re: Orbits of the Equator of the Sun

Post by neufer » Fri Aug 20, 2010 5:11 pm

Philosophaie wrote:Earth orbits about 7 Degrees above the Equator of the Sun. Can we discuss the actual orbit in Keplerian Data around the Sun's Equator and how the orbit relates to the Vernal Equinox.
The Earth has the most inclined orbit (7.155º) of all eight planets relative to the Sun's equator (moving from 7+ degrees below the Equator of the Sun to 7+ degrees above). As I understand it, the Earth currently passes into the northern hemisphere of the sun ~11.26° prior to vernal equinox (on around March 9th).
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Chris Peterson
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Re: Orbits of the Equator of the Sun

Post by Chris Peterson » Fri Aug 20, 2010 5:35 pm

Philosophaie wrote:In reguards to the Keplerian Orbit I am concerning with the orbit related to angles not using the Ecliptic but instead the orbit with the angles of the distance from the Sun's Equator. I am really interested how the Vernal Equinox points in a 3D orbit relative to the Sun. I know it points somewhere in Pisces. I just thought it would be interesting.
The analysis of the Earth's orbit around the Sun simply takes into consideration the center of mass of the Sun. That is, the Sun is seen as a point. You can define any plane as your reference- the Sun's equator, the ecliptic, the invariant plane- and all that changes is the value of the inclination.

Where the Earth is in its orbit at the vernal equinox changes over time, of course.
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Re: Orbits of the Equator of the Sun

Post by Philosophaie » Fri Aug 20, 2010 9:10 pm

Earth currently passes into the northern hemisphere of the sun ~11.26° prior to vernal equinox (on around March 9th).
I think you said on March 9 the orbit had a Sun longitude ~11.26 Degrees but no Sun latitude. Is there any way of getting this kind of information?

Do the Periapsis, Apoapsis and Vernal Equinox occur at regular intervals of Sun longitude and Sun latitude?

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Re: Orbits of the Equator of the Sun

Post by Chris Peterson » Fri Aug 20, 2010 9:40 pm

Philosophaie wrote:I think you said on March 9 the orbit had a Sun longitude ~11.26 Degrees but no Sun latitude. Is there any way of getting this kind of information?
All the orbital parameters you need are here.
Do the Periapsis, Apoapsis and Vernal Equinox occur at regular intervals of Sun longitude and Sun latitude?
They all occur annually at the same solar latitude and longitude (different for each, of course), excepting for a slow drift due to precession and various perturbations.
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Re: Orbits of the Equator of the Sun

Post by neufer » Fri Aug 20, 2010 9:51 pm

Philosophaie wrote:
Earth currently passes into the northern hemisphere of the sun ~11.26° prior to vernal equinox (on around March 9th).
I think you said on March 9 the orbit had a Sun longitude ~11.26 Degrees but no Sun latitude. Is there any way of getting this kind of information?
I am assuming that "Longitude of ascending node" for earth
is respect to the Sun's equator (and not the invariable plane)
but I could be wrong about that:
http://en.wikipedia.org/wiki/Earth wrote:
Inclination: 7.155° to Sun's equator / 1.57869° to invariable plane
Longitude of ascending node: 348.74°[-11.26°]
Philosophaie wrote:
Do the Periapsis, Apoapsis and Vernal Equinox
occur at regular intervals of Sun longitude and Sun latitude?
Yes and No. See: http://en.wikipedia.org/wiki/Milankovitch_cycles
Art Neuendorffer