$
\begin{tikzpicture}[baseline]
    \node (S) [circle,draw] {$S$};
    \draw (0,0) circle (1cm);
    \filldraw (S.157) circle (.5mm);
    \draw (S.180)-- (180:10mm);
    \draw (S.135)-- (135:10mm);
    \draw (S.90)-- (90:10mm);
    \draw (S.45)-- (45:10mm);
    \draw (S.0)-- (0:10mm);
    \draw (S.-45)-- (-45:10mm);
    \filldraw (112:1cm) circle (.5mm);
    \draw (S.-90)-- (-90:10mm);
    \draw (S.-135)-- (-135:10mm);
\end{tikzpicture}
= i \cdot 
\begin{tikzpicture}[baseline]
    \node (S) [circle,draw] {$S$};
    \draw (0,0) circle (1cm);
    \filldraw (S.157) circle (.5mm);
    \draw (S.180)-- (180:10mm);
    \draw (S.135)-- (135:10mm);
    \draw (S.90)-- (90:10mm);
    \draw (S.45)-- (45:10mm);
    \draw (S.0)-- (0:10mm);
    \draw (S.-45)-- (-45:10mm);
    \filldraw (157:1cm) circle (.5mm);
    \draw (S.-90)-- (-90:10mm);
    \draw (S.-135)-- (-135:10mm);
\end{tikzpicture}
$