\begin{table}%t3 \par \caption{\label{hlimtab}{$H$-band and mass limits obtained from the observations.} } %\centerline { \begin{tabular}{@{} l c l c c c @{}} \hline\hline Object & $H_{\rm lim} \pm 1\sigma$$^a$ & $ZP$$^b$ & $SE-2MASS-\rm limits$$^c$ & \citet{Curto2007} & Mass-limit$^d$ \\ & [mag] & [mag] & [mag] & [mag] & [Jupiter masses]\\ & & & & & \\ \hline PSR J0108-1431 & $21.42 \pm 0.16$ & 24.66 & $21.5 \pm 1.5$ & $\cdots$ & --\\ RX J0420.0-5022 & $21.84 \pm 0.16$ & 24.61 & $21.5 \pm 0.6$ & 21.7 & $\cdots$\\ Geminga$^e$ & $22.66 \pm 0.14$ & 24.66$^{\rm ep2}$ & $22.0 \pm 0.4$ & $\cdots$ &12\\ RX J0720.4-3125 & $23.07 \pm 0.11$ & 24.63$^{\rm ep2}$ & $22.3 \pm 0.4$ & 22.7 & 15\\ RX J0806.4-4123 & $22.64 \pm 0.16$ & 24.59 & $22.6\pm 0.4$ & 22.9& $\cdots$ \\ RX J1856.6-3754 & $21.54 \pm 0.24$ & 24.65$^{\rm ep2}$ & $22.1 \pm 0.4$ & 21.5 & 11\\ PSR J1932+1059 & $20.31 \pm 0.18$ & 23.49 & $\cdots$ & $\cdots$ & 42\\ RBS 1774 & $22.04 \pm 0.16$ & 24.67 & $21.6 \pm 1.0$ & 22.1& $\cdots$ \\ \hline \end{tabular}} \par \smallskip $^a$ {$H_{\rm lim}$ indicates the faintest $H$-magnitude with a detection SNR of three measured close to the position of the neutron star; The $1 \sigma$ error is a result of the \stf photometric error, the zeropoint error, and an estimated/assumed error from comparison with 2MASS;} $^b$ {$ZP$ states the magnitude of the zeropoints, which were obtained in the frame of ESO's calibration plan; $^{\rm ep2}$ indicates that two epochs have been used;} $^c$ {$SE-2MASS-limits$ lists the {{\it Source Extractor}} limits if using relative 2MASS photometry;} $^d$ {The mass-limit is according to Sect.~\ref{res1}, $\cdots$ notes that the found objects are interesting for a second epoch observation, -- states the opposite;} $^e$ {Geminga has been detected in a deeper HST ${\it F160W}$ observation with roughly 24.1~mag \citep{Shibanov2006}.} \end{table}