\begin{table}%T3 \par \caption{\label{table:1}GJ~436b timing measurements.} \small%\centerline { \begin{tabular}{c c c c} \hline \hline $T_{\rm C}$ (HJD) & $\sigma_{T_{\rm C}}$ (d) & Epoch & Reference \\ \hline 2454222.61612 & 0.00037 & 0 & (1)\\ 2454225.26029 & 0.00038 & 1 & (1)$^a$\\ {\bf 2454238.47898} & {\bf 0.00040} & {\bf 6} & {\bf This work}\\ 2454243.76657 & 0.00026 & 8 & (1)\\ 2454246.40982 & 0.00040 & 9 & (1)\\ 2454251.69956 & 0.00030 & 11 & (1)\\ 2454280.78165 & 0.00017 & 22 & (2,3,4)$^b$\\ 2454439.41607 & 0.00068 & 82 & (5)\\ 2454444.70385 & 0.00093 & 84 & (5)\\ 2454447.34757 & 0.00080 & 85 & (5)\\ 2454463.20994 & 0.00089 & 91 & (5)\\ 2454468.49911 & 0.00094 & 93 & (5)\\ 2454505.51379 & 0.00050 & 107 & (6)\\ 2454534.59584 & 0.00015 & 118 & (7)\\ 2454558.39010 & 0.00063 & 127 & (6)\\ 2454587.47447 & 0.00061 & 138 & (6)\\ \hline \end{tabular}} \smallskip References: (1) \citet{shporer_etal08}; (2) \citet{gillon_etal07b}; (3) \citet{deming_etal07}; (4) \citet{southworth08}; (5) \citet{bean_and08}; (6) \citet{ribas_etal09}; (7) \citet{alonso_etal08}. \\ $^a$ Average of the two values given for this epoch.\\ $^b$ Average of the three values given by different authors for this epoch, considering the correction given by Bean et~al. (2008). \end{table}