\documentclass[pstricks]{standalone}
\usepackage{multido,pst-kepler,animate}
\begin{document} 
\multido{\rB=\FloatToFix{\Einitial}+\FloatToFix{\DeltaEinitial}}{\TotalNumberOfFrames}{%
  \begin{pspicture}[showgrid](1,-2)(13,6)
    \psset{dotscale=0.8}\psset{PointSymbol=*,plotpoints=600,arrowscale=1.4,arrowinset=0.05,arrowlength=2}
    \pnode(\Ox,\Oy){O}\pnode(\Fiix,\Fiiy){F_2}
    \pstEllipse[linecolor=black,linewidth=1pt](O)(\ael,\bel)
    \CalculeEtAffichePoint
        {\FloatToFix{\rB}}%
        {\AreaFractionOfTotal}%
        {$A_{1/2} \approx \num{\xintDecToString{\xintfloateval{[3]\AreaStart}}}$}%
    \CalculeEtAffichePoint[green]
      {\FloatToFix{\rB+120}}%
      {\AreaFractionOfTotal}%
      {$A_{3/4}\approx \num{\xintDecToString{\xintfloateval{[3]\AreaStart}}}$}%
\psdot[dotstyle=o,dotscale=1,fillcolor=orange](F_2)
            \uput{0.15}[-90]{0}(F_2){$S$}
            \pstEllipse[linecolor=purple,linestyle=none,arrows=->](O)(\ael,\bel)[260][270]
            \pstEllipse[linecolor=purple,linestyle=none,arrows=->](O)(\ael,\bel)[80][90]
\end{pspicture}}
\end{document}
