\begin{table}%t1
\caption{Literature determinations of atmospheric parameters for
$\alpha$~Cen~ A and B.}  \label{hist-review}
\small%\centerline
{
\begin{tabular}{lcc ccc cc}
\hline\hline
\multicolumn{8}{c}{\bf{$\alpha$~Centauri~A}}\\ 
Reference&\multicolumn{4}{c}{Atmospheric
parameter}&&\multicolumn{2}{c}{Method
used}\\
%\cline{2-5}\cline{7-8}
&\Teff(K)&$\log g$&$\xi_t$ (km~s$^{-1}$)&$\rm [Fe/H]$
&&\Teff&$\log g$\\\hline
French \& Powell (\cite{French1971})            & 5770 &   --  &  --   &$+$0.22&&$a$  &--   \\
Soderblom (\cite{Soderblom1986})                   & 5770 &   --  &  --   &  --    &&$b$  &--   \\
England (\cite{England1980})                     & 5750 & 4.38 & 1.0  &$+$0.28&&$b,c,d$&$c,d$\\
Bessell (\cite{Bessell1981})                     & 5820 & 4.25 & 1.7  &$-$0.01&&$a,e$ &$e$ \\
Smith et~al. (\cite{Smith1986})                & 5820 & 4.40 & 1.54 &$+$0.20&&$a,e$ &$d$ \\
Gratton \& Sneden (\cite{Gratton1987})           & 5750 & 4.38 & 1.2  &$+$0.11&&$f$  &$c,e$\\
Abia et~al. (\cite{Abia1988})                 & 5770 & 4.5  & 1.0  &$+$0.22&&$b$  &$f$ \\
Edvardsson (\cite{Edvardsson1988})                  & --    & 4.42 & --    &$+$0.28&&--    &$d$ \\
Furenlid \& Meylan (\cite{Furenlid1990})          & 5710 & 4.27 & 1.0  &$+$0.12&&$a,e$ &$e$ \\
Chmielewski et~al. (\cite{Chmielewski1992})          & 5800 & 4.31 & --    &$+$0.22&&$b$  &$c$ \\
Neuforge-Verheecke \& Magain (1997)& 5830 & 4.34 & 1.09 &$+$0.25&&$a$  &$ce$\\
Allende-Prieto et~al. (\cite{Allende2004})       & 5519 & 4.26 & 1.04 &$+$0.12&&$f$  &$c$ \\
Doyle et~al. (\cite{Doyle2005})                & 5784 & 4.28 & 1.08 &$+$0.12&&$direct$  &$direct$ \\
Santos et~al. (\cite{Santos2005})               & 5844 & 4.30 & 1.18 &$+$0.28&&$a$  &$a$ \\
del Peloso et~al. (2005a)          & 5813 & 4.30 & 1.23 &$+$0.26&&$b,f$&$c$ \\
Valenti \& Fischer (\cite{Valenti2005})          & 5802 & 4.33 & --    &$+$0.23&&$a$  &$e$ \\
This work                          & 5824 & 4.34 & 1.46 &$+$0.24&&$a,b,e,f$&$c,e$ \\
 \hline
%                                   &      &      &      &       &&     &    \\\hline
\multicolumn{8}{c}{\bf{$\alpha$~Centauri~B}}\\
%\cline{1-8}
Reference&\multicolumn{4}{c}{Atmospheric
parameter}&&\multicolumn{2}{c}{Method
used}\\
%\cline{2-5}\cline{7-8} 
&\Teff(K)&$\log
g$&$\xi_t$ (km~s$^{-1}$)&$\rm [Fe/H]$&&\Teff&$\log
g$\\
\hline
French \& Powell (\cite{French1971})             & 5340 &  --   & --    &$+$0.12&&$a$  &--   \\
Soderblom (\cite{Soderblom1986})                    & 5350 &  --   & --    &  --    &&$b$  &--   \\
England (\cite{England1980})                      & 5260 & 4.73 & 1.1  &$+$0.38&&$b,c,e$&$c,e$\\
Bessell (\cite{Bessell1981})                      & 5350 & 4.5  & 1.0  &$-$0.05&&$a,e$ &$e$ \\
Smith et~al. (\cite{Smith1986})                 & 5280 & 4.65 & 1.35 &$+$0.20&&$a,e$ &$d$ \\
Gratton \& Sneden (\cite{Gratton1987})            & 5250 & 4.50 & 1.0  &$+$0.08&&$f$  &$c,e$\\
Abia et~al. (\cite{Abia1988})                  & 5300 & 4.5  & 1.5  &$+$0.14&&$b$  &$f$ \\
Edvardsson (\cite{Edvardsson1988})                   & --    & 4.65 & --    &$+$0.32&&--    &$d$ \\
Chmielewski et~al. (\cite{Chmielewski1992})           & 5325 & 4.58 & --    &$+$0.26&&$b$  &$c$ \\
Neuforge-Verheecke \& Magain (1997) & 5255 & 4.51 & 1.00 &$+$0.24&&$a$  &$c,e$\\
Allende-Prieto et~al. (\cite{Allende2004})        & 4970 & 4.59 & 0.81 &$+$0.18&&$f$  &$c$ \\
Santos et~al. (\cite{Santos2005})                & 5199 & 4.37 & 1.05 &$+$0.19&&$a$  &$a$ \\
Valenti \& Fischer (\cite{Valenti2005})           & 5178 & 4.56 & --    &$+$0.22&&$a$  &$e$ \\
This work                           & 5223 & 4.44 & 1.28 &$+$0.25&&$a,b,e,f$ &$c,e$ \\
\hline
\end{tabular} }
\smallskip
The notation used from Cols.~6 to~7
stands for: $a$~excitation equilibrium; $b$~wings of Balmer
lines; $c$~trigonometric parallax; $d$~wings of strong lines;
$e$~ionization equilibrium; $f$~photometric color indexes;
$direct$   directly-measured luminosity, mass and radius. Note
that, generally, the microturbulence velocities have not the same
zero point and cannot be directly compared. Typical errors,
respectively, in $T_{\rm eff}$, $\log g$, and [Fe/H] are $\leq$100 K, $\leq$0.2~dex, and $\leq$0.1~dex, but note that these estimates usually
do not include systematic uncertainties, and that not all authors
provide error determinations, or labor under the same definitions
for them. 
\end{table}