\begin{table}%t2
\caption{Adopted temperature scales with validity range in MK spectral type, luminosity class, method of construction, intrinsic errors and validity range of the intrinsic errors. 
We distinguish between calibrations which are based directly on effective temperature measurements and those only derived from calibrations of other authors. We refer to the former as {\it primary} and to the latter as {\it derived} scales. Scales based on older calibrations but that account for new measurements are indicated by "improved''. The origin of the intrinsic errors is explained in Appendix~\ref{app:errors}. %The scales of \citet{Luhman99} and \citet{Luhman03} are not used in this work but shown for completeness.
\label{tab:scales}}
%\centerline
{\begin{tabular}{l|lllll}
\hline
\hline
reference&sp. type&lum. class&construction&intrinsic errors&validity range of int. errors\\
\hline
\citet[ Table~2]{Bessell79}$^1$&B7-M~6&dwarfs&primary&220~K$^2$&earlier G2\\
&&&&$\Delta{\log}T_{\rm eff}=0.035^2$&later than G2\\
&&&&&and earlier than K7\\
\citet[ Table~2]{Bessell91}$^1$& K~7-M~7.5&dwarfs&primary&290~K$^2$&whole range\\
\hline
\citet[ Table~3]{Bessell79}&G7-M~6&giants&primary&220~K$^2$&whole range\\
\hline
\citet[ Table~7]{CK79}&O9.5-M~6&dwarfs&derived&300~K$^2$&whole range\\
\hline
\citet[ Table~5]{dJN87}&O3-M~9&dwarfs&primary&$\Delta{\log}T_{\rm eff}=0.021^3$&whole range\\
\hline
\citet[ Table~5]{dJN87}&O3-M~9&subgiants&primary&$\Delta{\log}T_{\rm eff}=0.021^3$&whole range\\
\hline
\citet[ Table~5]{dJN87}&O3-M~9&giants&primary&$\Delta{\log}T_{\rm eff}=0.021^3$&whole range\\
\hline
\citet[ Table~4]{HSS94}&F0-M~6&dwarfs&derived&$\Delta{\log}T_{\rm eff}=0.015^2$&earlier than K7\\
&&&&290~K$^2$&later than K7\\
\hline
\citet[ Table~5]{KH95}&B0-M~6&dwarfs&improved&$\Delta{\log}T_{\rm eff}=0.015^2$&whole range\\
\hline
\citet[ Table~5]{Perrin98}&G8-M~8&giants&primary&220~K$^2$&earlier than M~6\\
&&&&79~K$^3$&M~6\\
&&&&94~K$^3$&M~7\\
&&&&42~K$^3$&M~8\\
\hline
\citet[ Table~2]{Luhman99}&M~1-M~9&giants&derived&270~K$^2$&earlier than M~7\\
&&&&100~K$^2$&M~7\\
&&&&50~K$^2$&M~8\\
&&&&150~K$^2$&M~9\\
\hline
\citet[ Fig.~8]{Luhman03}&M~1-M~9&dwarfs&improved&80~K$^2$&whole range\\
\hline
\citet[ Table~8]{Luhman03}&M~1-M~9&intermediate&improved&80~K$^2$&earlier than M~6.5\\
&&&&100~K$^2$&later than M~6.5\\
\hline
\citet[ Table~7.6]{Tokunaga00}&O9-M~6&dwarfs&derived&100~K$^3$&later spectral types\\
\hline
\end{tabular}}
\par
\smallskip\smallskip
$^1$We only used a combination, i.e. \citet{Bessell79} for spectral types earlier than K7 and \citet{Bessell91} for spectral types later than K7.\\
$^2$Intrinsic errors were derived by us or taken from another work.\\
$^3$Intrinsic errors were adopted from the original work.
\end{table}