Monday, September 27, 2021

Delaunay Variable Problem Solution

 First obtain the perturbation term R in terms of Legendre functions:

R=  k 2  3    [ 1/  r 3 +  ½  2/ r 3 3 - 3/2  2/ r 3 3  cos 2 S 

If we take  m =  mass of Jupiter,  m = mass  of Earth, and a =  semi-major axis of Jupiter we can calculate the first order perturbations in L, G,  ℓ and g using the reference Hamiltonian:

  =  

 -  m 2 / 2 L 2  -  2  3    [1/  r 3 +  ½  2/ r 3 3 - 3/2  2/ r 3 3  cos 2 S 

We thereby obtain a functional Hamiltonian:

 (L, G,  ℓ,  g, m 2 , m 3  ,  a 3  ,  t)  

And can write out the differential equations to solve the problem.  One such equation would be:

dL/ dt =      /  ℓ         

  Integration yielding:

L  -  L o =   ò t  o      F (ℓ)   dt    

Where F (ℓ)  =  F(L, G,  ℓ ,  g, constants, t) 

We  then substitute for each of the variables: L, G etc. Earth and Jupiter values, and also:    

 ℓ   -  ℓ  o  ,   g   -   g  o  ,   etc.  leaving everything else constant and taking the specific integral in each case.  Do this for L, G,  ℓ and g

Using the  mass values for Jupiter and Earth  expressed in terms  of solar (m )
 
m =  1/ (1047.355 m ☉ )

m =  1/( 32930 m ☉ )   

   =  5.2 AU  

 

On computation using the preceding, we get an error in the reference Hamiltonian:  

  =  2  3    10   -2

For an error magnitude e  »   0.012

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