Adding space between subfigures of tikzpicture (for caption)

Question

I'm trying to draw two figures next to each others using tikzpicture. It's working fine, but the caption of the sub-figures is looking weird.

I tried adding the \qquad's, but I'm still having the same problem.

Here's my code;

\documentclass{article}
\usepackage{tikz,subfigure}
\begin{document}
\begin{figure}[!hb]%
\centering
\subfigure[Caption for subfigure 1]{
\begin{tikzpicture}[every node/.style={circle,draw}]
\node{5};
\end{tikzpicture}
}
\qquad\qquad\qquad
\subfigure[Caption for subfigure 2]{
\begin{tikzpicture}[every node/.style={circle,draw}]
\node{}
        child{node{}}
        child[missing];
\end{tikzpicture}
}
\caption{}%
\label{}%
\end{figure}

\end{document}

Here's the resulting image

Answer 1

It's a bounding box problem. you can add a node with [minimum width=xxxcm]

\documentclass{article}
\usepackage{tikz,subfigure}
\begin{document}
\begin{figure}[!hb]%
\centering
\subfigure[Caption for subfigure 1]{
\begin{tikzpicture}
\begin{scope}[every node/.style={circle,draw}]
\node(a){5};
\end{scope}
\node[minimum width=3.5cm] at (a){};
\end{tikzpicture}
}
\qquad\qquad\qquad
\subfigure[Caption for subfigure 2]{
\begin{tikzpicture}

\begin{scope}[every node/.style={circle,draw}]
\node(a){}
        child{node{}}
        child[missing];

\end{scope}
  \node[minimum width=3.5cm] at (a){};      
\end{tikzpicture}
}
\caption{}%
\label{}%
\end{figure}

\end{document}