# Recreating this image using Tikz with flattened circle

I am trying to recreate this image:

I'm however struggling with the flattened circle shape in the centre as well as getting the curved lines for focusing. My current attempt has allowed me to get this far:

\begin{tikzpicture}
\draw (0,0) circle (2.4);
\draw [red, dashed] (0,0) circle (1.8);
\draw [<-, red, thick] (1.3,1.3) -- (2.3,2.3) node[above] {equilibrium orbit};
\draw    (0,2.4) to[out=-50,in=130] (0,-2.4);
\draw    (1.8,1.6) to[out=-60,in=100] (-1.85,-1.5);
\draw    (-2.1,1.2) to[out=40,in=220] (2.1,-1.2);
\end{tikzpicture}


This produces the pictures below:

However I am struggling to get any further.

Something like this?

\documentclass[tikz,border=3mm]{standalone}
\begin{document}
\begin{tikzpicture}[font=\sffamily,
declare function={rr(\t)=1.8*(1+0.01*rnd)*(1+0.1*sin(-45+3*\t));}]
\draw plot[smooth cycle,variable=\t,samples at={0,10,...,350}] (\t:{rr(\t)});