7. Connect the right focus $F_{2}$ of the ellipse $\frac{x^{2}}{9}+\frac{y^{2}}{4}=1$ with a moving point $A$ on the ellipse, and construct a square $F_{2} A B C\left(F_{2} 、 A 、 B 、 C\right.$ are arranged in a clockwise direction). Then, as point $A$ moves around the ellipse once, the trajectory equation of the moving point $C$ is $\qquad$
$\begin{array}{l}\text { 7. } \frac{(x-\sqrt{5})^{2}}{4}+\frac{(y-\sqrt{5})^{2}}{9} \\ =1\end{array}$

The translation is as follows:

$\begin{array}{l}\text { 7. } \frac{(x-\sqrt{5})^{2}}{4}+\frac{(y-\sqrt{5})^{2}}{9} \\ =1\end{array}$