\begin{table}%t1 %\centering \par \caption{\label{log}Spectroscopic observations.} \begin{tabular}{c c c c c c c c c c} \hline\hline \noalign{\smallskip} Object & $J$\tablefootmark{b} & Opt. & Instrument & Date & $T_{\rm exp}$\tablefootmark{d} & Airmass & $\Delta$airmass$_{\rm T-S}$ & $S/N$ & Near-IR \\ & (mag) & SpT\tablefootmark{c} & & & (min) & & & & SpT\\ \hline\noalign{\smallskip} \object{PPl~1} & 15.36 $\pm$ 0.01 & M6.5 & NICS($JHK$) & 2002 Oct. 31 & 8 $\times$ 2 & 1.08 & 0.14 & 50 & M7.0 $\pm$ 0.5 \\ \object{Calar~3} & 16.08 $\pm$ 0.01 & M8 & NICS($JHK$) & 2002 Oct. 31 & 8 $\times$ 2 & 1.15 & 0.07 & 49 & M8.0 $\pm$ 0.5 \\ \object{Teide~1} & 16.21 $\pm$ 0.01 & M8 & NICS($JHK$) & 2002 Nov. 27 & 8 $\times$ 2 & 1.03 & 0.73 & 32 & M8.0 $\pm$ 0.5 \\ \object{BRB~17} & 17.41 $\pm$ 0.03 & ... & LIRIS($zJ,HK$) & 2006 Dec. 28 & (12, 18) $\times$ 2 & 1.74, 1.41 & 0.44, 0.89 & 4, 6 & L0.0 $\pm$ 1.0 \\ \object{PLIZ~28} & 17.60 $\pm$ 0.04 & ... & NICS($JHK$) & 2005 Nov. 20 & 15 $\times$ 2 & 1.11 & 0.57 & 18 & L0.0 $\pm$ 1.0 \\ \object{PLIZ~35} & 18.07 $\pm$ 0.05 & ... & NICS($JHK$) & 2005 Sep. 18 & 65 $\times$ 0.6 & 1.03 & $-$0.03 & 15 & L2.0 $\pm$ 1.0 \\ \object{BRB~21} & 18.14 $\pm$ 0.06 & ... & NICS($JHK$) & 2005 Sep. 18 & 80 $\times$ 0.5 & 1.21 & 0.15 & 7 & L3.0 $\pm$ 1.0 \\ \object{BRB~23} & 18.23 $\pm$ 0.04 & ... & NICS($JHK$) & 2007 Feb. 7 & 10 $\times$ 5 & 1.33 & $-$0.27 & 14 & L3.5 $\pm$ 1.0 \\ \object{BRB~29} & 18.69 $\pm$ 0.10 & ... & LIRIS($HK$) & 2006 Dec. 29 & 12 $\times$ 2 & 1.09 & $-$0.02 & 3 & L4.5 $\pm$ 1.5 \\ \hline J0829\tablefootmark{a} & 12.80 $\pm$ 0.03 & L2V & LIRIS($zJ,HK$) & 2006 Dec. 28 &(4, 6) $\times$ 1.5 & 1.38, 1.36 & 0.80, 0.94 & 29, 37& L2.0 $\pm$ 1.0 \\ \hline \end{tabular} \tablefoot{\tablefoottext{a}{\object{SSSPM~J0829$-$1309}.} \tablefoottext{b}{From the Galactic Clusters Survey (GCS) component of UKIDSS \citep[][sixth data release]{lawrence2007} for the Pleiades members and from 2MASS \citep{skrutskie2006} for the field object.} \tablefoottext{c}{From \citet{martin1996} for the three Pleiades objects and from \citet{scholz2002} and \citet{lodieu2005} for the field object.} \tablefoottext{d}{Dithers $\times$ detector integration time.} } \vspace*{3mm} \end{table}