Analytic GR solutions of S2-star orbits and precession 732” per revolution
New initial data 2020 is used. My earlier initial data was 2016 in my
postings in this sci.physics.relativity.
Please also take a look my two postings about OJ287 in sci.astro. I have got
no comments there due so heavy traffic of unbssinesslike postings from many posters.
(Only command lines of Maple 9 program is below and command line mark is >. This can be copy-pasted in Maple 9 program and run it.
Remark that for example e-2 below means 10^(-2)
or e2 below means 10^2.)
Best Regards,
Hannu Poropudas
Finland
---COPY of the Maple 9 program below------
> # RIGHT: Particle in Schwarzschild metrics H.P. 09.09.2020
> # S2 Orbit around Sagittarius A*
> # Perihelion precession of S2.
> #OK=COMPARISION to Post-Newtonian approx of Abuter R et al 2020, A&A 636,L5(2020)
> # Abuter R. et al. 2020. Detection of the Schwarzschild precession in the
> # orbit of the star S2 near the Galactic centre massive black hole.
> # Astronomy Astrophysics, 636, L5 (2020).
> # In this article: 12'/rev=720"/rev,12.1'/rev=726"/rev, 12.3'/rev=738"/rev
> # My GR calculation below, result :
731.8543470"/rev OR -676.7436912"/rev
> # (I use not rounded numbers). Approximately 732"/rev OR -677"/rev.
> # New starting values from Table E.1 Best-fit Orbit Parameters above article
> # and other constants of physics are taken from Wikipedia date 9.9.2020.
> # NEW CALCULATION x and y are roots. E and J little changed.
> # (analytic solutions defined between roots a2..a1 OR a4..a3)
>Restart;
>with(plots):with(plottools):
> # GEOMETRIZED UNIT SYSTEM IS PROBLEMATIC.
> # Ref. Formulae for E and J from Weinberg's book. (THESE FORMULAE ARE NOT USED.)
> # Reference: Weinberg, S. 1972. Gravitation and Cosmology: Principles
> # and Applications of the General Relativity. Wiley, New York. pp. 179-210.
> # (units c = 1, and c.g.s in Weinberg's book).
> # J = r^2*dPhi/dp = constant (angular momentum per unit mass), p. 186.
> # E = constant (energy per unit mass), p. 186.
> # E > 0 for material particles, E = 0 for photons. p. 186.
> # Integration limits must be determined from the problem to which apply these.
>#Int(1/(r^4*(1/J^2-E/J^2)+r^3*(2*M*G*E/J^2)-r^2+2*M*G*r)^(1/2),r);
>AU := 149597870700*10^2;
># 125.058 mas, 8246.7 pc, 1 pc =3.26 ly
>ap:= 1030.799324*AU;
>em := 0.884649;
>M := 4.261*10^6*1.98847*10^30*10^3;
># v = c
>v := 2.99792458*10^8*10^2;
>G := 6.6743015*10^(-11)*10^3;
># BH mass*G geometric units (cm) and v = c.
>M*G/v^2;
>MG := 0.6292090968e12;
> # EXAMPLE. Weinberg formulae E and J (THESE FORMULAE ARE NOT ANY MORE USED.)
> # Perihelion distance
>x := ap*(1-em);
># Aphelion distance
>y := ap*(1+em);
> # NEW CALCULATION (NEW FORMULAE OF MY OWN) x and y are roots
> #***********************************************************
>E := (2*x*y*MG+2*y^2*MG+2*x^2*MG-x^2*y-x*y^2)/((-y+2*MG)*(-2*x*MG-2*y*MG+x^2+x*y));
>J := 2^(1/2)*(-(-y+2*MG)*MG*(-2*x*MG-2*y*MG+x^2+x*y))^(1/2)*y*x/(-x^2*y+2*x^2*MG-4*x*MG^2+4*x*y*MG-x*y^2+2*y^2*MG-4*y*MG^2);
> #*****************************************************************
>
> # Weinberg's formula (NOT USED ANY MORE)
> #J := sqrt((1/(1-2*MG/y)-(1/(1-2*MG/x)))/(1/y^2-1/x^2));
> # NEW CALCULATION x and y are roots
>J := -0.4594478956e14;
> # Weinberg's formula (NOT USED ANY MORE)
> #E := (y^2/(1-2*MG/y)-x^2/(1-2*MG/x))/(y^2-x^2);
> # NEW CALCULATION x and y are roots
>E := 1.000040803;
>solve(r^4*(1/J^2-E/J^2)+r^3*(2*MG*E/J^2)-r^2+2*MG*r=0,r);
>a1 := 0.2906262559e17;
>a2 := 0.1778773310e16;
>a3 := 0.1259363679e13;
>a4 := 0;
># Primitive function, definition areas 0<=P<=Pi/2 and a2 <= r <= a1.
>e := P -> 2.000794538*EllipticF(sin(P),0.2578161452e-1);
>r := P -> (0.3436029258e29*sin(P)^2-0.5169358260e32)/(0.2728385228e17*sin(P)^2-0.2906136623e17);
> #******************************
> # P which corresponds to the perihelion distance (TWO VALUES)
>solve((0.3436029258e29*sin(P)^2-0.5169358260e32)/(0.2728385228e17*sin(P)^2-0.2906136623e17)=0.1778774525e16,P);
>e(0.8532953281e-3);
>e(-0.8532953281e-3);
># Solution's definition area limit is a2-root (TWO VALUES)
>solve((0.3436029258e29*sin(P)^2-0.5169358260e32)/(0.2728385228e17*sin(P)^2-0.2906136623e17)=0.1778773310e16,P);
>e(0.6516324491e-5);
>e(-0.6516324491e-5);
># P which corresponds to the aphelion distance (TWO VALUES)
>solve((0.3436029258e29*sin(P)^2-0.5169358260e32)/(0.2728385228e17*sin(P)^2-0.2906136623e17)=0.2906230228e17,P);
>e(1.569945054);
>e(-1.569945054);
> # Solution's correct definition limit is a1-root (TWO VALUES)
> # COMPLEX NUMBER (SMALL COMPLEX PARTS ARE LITTLE OUTSIDE ORBIT)
>solve((0.3436029258e29*sin(P)^2-0.5169358260e32)/(0.2728385228e17*sin(P)^2-0.2906136623e17)=0.2906262559e17,P);
>e(1.570796327-0.1136598102e-4*I);
>e(-1.570796327+0.1136598102e-4*I);
> # Angle change, definition areas 0<=P<=Pi/2 ja a2 <= r <= a1.
> # + sign perihelion in last term
>e2 := P -> 2*abs(2.000794538*EllipticF(sin(P),0.2578161452e-1)-2.000794538*EllipticF(sin(0.8532953281e-3),0.2578161452e-1))-2*Pi;
>r2 := P -> (0.3436029258e29*sin(P)^2-0.5169358260e32)/(0.2728385228e17*sin(P)^2-0.2906136623e17);
> # Calculation of different combinations of + and - signs
> # - sign perihelion in last term
>e2B := P -> 2*abs(2.000794538*EllipticF(sin(P),0.2578161452e-1)-2.000794538*EllipticF(sin(-0.8532953281e-3),0.2578161452e-1))-2*Pi;
>r2B := P -> (0.3436029258e29*sin(P)^2-0.5169358260e32)/(0.2728385228e17*sin(P)^2-0.2906136623e17);
> # Angle change in radians per one revolution. (TWO e2 and e2B functions)
> # FOR e2
>evalf(e2(1.569945054));
># Angle change in degrees per one revolution.
>evalf(-0.3280946e-2*180/Pi);
># Angle change in arc seconds per one revolution.
>-0.1879843586*60*60;
>###(-676.7436912)
># Second root
>evalf(e2(-1.569945054));
>evalf(0.3548130e-2*180/Pi);
>0.
2032928741*60*60;
>###
(731.8543470)
># FOR e2B
>evalf(e2B(1.569945054));
># Angle change in degrees per one revolution.
>evalf(0.3548130e-2*180/Pi);
># Angle change in arc seconds per one revolution.
>0.
2032928741*60*60;
>###
(731.8543470)
># Second root
>evalf(e2B(-1.569945054));
>evalf(-0.3280946e-2*180/Pi);
>-0.1879843586*60*60;
>####(-676.7436912)
> # + and - signs for e2 or e2B does not have different results due abs-values
> # Second Primitive function, definition areas 0<=P<=Pi/2 and a4=0 <= r <= a3.
> # This has form of spiral (+ and - signs) which leads to the origin.
>
> # SUMMARY of S2 precession:
731.8543470"/revolution OR -676.7436912"/revolution.
>
> #******************************
># Second Primitive function, definition areas 0<=P<=Pi/2 and a4=0 <=
r <= a3.
>ee := P-> 2.000794538*EllipticF(sin(P),0.9996675989);
>rr := P-> (0.3660041508e29*sin(P)^2)/(0.1259363679e13*sin(P)^2+0.2906136623e17);
> #*********************************************************
>
> # Plottings only on definition area a2..a1.
> # First side of the solution (+,- solution)
>plot([r(P),e(P),P=0..Pi/2],coords=polar);
># Second side of the solution (+,- solution)
>plot([r(P),-e(P),P=0..Pi/2],coords=polar);
># Angle change picture has no other meaning than above calculated precession
>plot([r2(P),e2(P),P=0..Pi/2],coords=polar);
># Angle change picture has no other meaning than above calculated precession
>plot([r2B(P),e2B(P),P=0..Pi/2],coords=polar)
> # Plottings only on definition area a4..a3.
> # First side of the Second solution (+,- solution)
>plot([rr(P),ee(P),P=0..Pi/2],coords=polar);
># Second side of the Second solution (+,- solution)
>plot([rr(P),-ee(P),P=0..Pi/2],coords=polar);