\begin{table}%t1
\caption{\label{tab:observations}Dates of observations, instruments and configurations used. }
\small%\centerline
 {
\begin{tabular}{cc|ll}
\hline\hline
&&& \\[-8pt]
Date       & MJD & Instrument & Configuration$^{a}$ \\
\hline
07/06/2002 & 52~432.2 & EMMI   & REMD, 2 $\times$ 2, GRAT7 \\
06/06/2003 & 52~796.0 & EMMI   & REMD, 2 $\times$ 2, GRAT7 \\
07/06/2003 & 52~797.1 & EMMI   & REMD, 1 $\times$ 1, GRAT6 \\
21/09/2003 & 52~903.0 & UVES   & RED,~580,~CD3 \\
           &         &        & RED,~860,~CD4 \\
03/04/2004 & 53~098.4 & UVES   & RED,~580,~CD3 \\
           &         &        & RED,~860,~CD4 \\
           &         &        & DICHR1,~564,~CD3\\
09/06/2004 & 53~165.2 & UVES   & RED,~580,~CD3 \\
           &         &        & RED,~860,~CD4 \\
           &         &        & DICHR1,~564,~CD3\\
07/07/2004 & 53~193.1 & UVES   & DICHR1,~564,~CD3\\
10/07/2004 & 53~196.2 & UVES   & RED,~580,~CD3 \\
           &         &        & RED,~860,~CD4 \\
           &         &        & DICHR1,~564,~CD3\\
28/09/2004 & 53~276.0 & UVES   & RED,~580,~CD3 \\
           &         &        & RED,~860,~CD4 \\
           &         &        & DICHR1,~564,~CD3\\
25/03/2005 & 53~454.3 & FLAMES & MEDUSA, LR6 \\
           &         &        & MEDUSA, LR8 \\
29/05/2005 & 53~519.3 & FLAMES & MEDUSA, LR6 \\
           &         &        & MEDUSA, LR8 \\
13/07/2005 & 53~564.1 & FLAMES & MEDUSA, LR6 \\
           &         &        & MEDUSA, LR8 \\
17/02/2006 & 53~783.4 & EMMI   & RILD, 1 $\times$ 1, GRISM6 \\
29/06/2008 & 54~646.2 & FLAMES & MEDUSA, HR21 \\
18/07/2008 & 54~665.0 & FLAMES & MEDUSA, HR21 \\
24/07/2008 & 54~671.1 & FLAMES & MEDUSA, HR21 \\
14/08/2008 & 54~692.0 & FLAMES & MEDUSA, HR21 \\
04/09/2008 & 54~713.0 & FLAMES & MEDUSA, HR21 \\
15/09/2008 & 54~724.1 & FLAMES & MEDUSA, HR21 \\
19/09/2008 & 54~728.1 & FLAMES & MEDUSA, HR21 \\
25/09/2008 & 54~734.1 & FLAMES & MEDUSA, HR21 \\
14/05/2009 & 54~965.2 & FLAMES & MEDUSA, HR21 \\
18/05/2009 & 54~969.3 & FLAMES & MEDUSA, HR21 \\
\hline 
\end{tabular}}
\medskip
$^{a}$ The VLT/UVES configurations list the instrument mode (RED or DICHR\#1), central wavelength (nm) and cross-disperser (CD\#3 or CD\#4). The NTT/EMMI configurations list the observing mode (REMD or RILD), binning and grating, while the VLT/FLAMES configurations list the GIRAFFE spectrograph mode and setup name.
\end{table}