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-   -   2-body or more orbit systems? (http://www.physicsforums.com/showthread.php?t=162666)

 mrjoe2 Mar26-07 02:30 PM

2-body or more orbit systems?

Well, my biggest q, isn't exactly about the 2-body, it's more like 3-body I guess.
What I'm trying to accomplish here is to say that we can not ignore a small third mass orbiting around a sun-like object.

I have the Sun-Like Object and another object (L) orbiting around it, now L is following an ellipse shape because the center Sun object is having a gravitation pull on m1. Now a smaller object (K) further away is also being affected by the gravitational pull by the Sun object but even L has a gravitational pull on K, so that K object is (having 2 gravitational pulls effecting it)?
And this cuases turbulation which is why the ellipse is squiggly?
Does this make any sense or am I to ambiguous?

Another question is: Consider kepler's first law. The planets orbit is an eiplse since it's binding energy is near 0 but not equal to 0. As planets orbit around a sun we can see that the distance from the sun on the planet's position is not constant. Can it be constan is my question? When, how?

 mrjoe2 Mar26-07 02:31 PM

Replace m1 with L.
Quote:
 Quote by mrjoe2 (Post 1284284) Well, my biggest q, isn't exactly about the 2-body, it's more like 3-body I guess. What I'm trying to accomplish here is to say that we can not ignore a small third mass orbiting around a sun-like object. I have the Sun-Like Object and another object (L) orbiting around it, now L is following an ellipse shape because the center Sun object is having a gravitation pull on m1. Now a smaller object (K) further away is also being affected by the gravitational pull by the Sun object but even L has a gravitational pull on K, so that K object is (having 2 gravitational pulls effecting it)? And this cuases turbulation which is why the ellipse is squiggly? Does this make any sense or am I to ambiguous? Another question is: Consider kepler's first law. The planets orbit is an eiplse since it's binding energy is near 0 but not equal to 0. As planets orbit around a sun we can see that the distance from the sun on the planet's position is not constant. Can it be constan is my question? When, how?

 MeJennifer Mar26-07 02:38 PM

There are already enough complications with one body in orbit, since both bodies will eventually meet due to gravitational radiation.
Add a third and the problem space is exploding.

 tony873004 Mar26-07 04:10 PM

The reason for your "squiggly ellipse" is because you're probably displaying your orbit with the central star locked to the middle of your diagram, when in reality, it is not still. It orbits the barycenter of the AB pair. If you plot your orbits with respect to the barycenter, the squigglies should go away.

Here is an example. This is a screen shot of a 1 solar mass star being orbited by a 0.5 solar mass star from a distance of 0.1 AU and an eccentricity of 0.2. A more distant massless test particle orbits the pair. With the central star locked in place in the plot, the distant object has the squiggles. But when the plot is centered on the barycenter of the AB pair, it does not:

http://orbitsimulator.com/PF/bc.GIF

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