\begin{table}%t1
\caption{Experimental radiative lifetimes in Os~II.\label{oslifetimes}}
%\centerline
{
\begin{tabular}{lcccr}
\hline \hline 
\multicolumn{1}{c}{Level$^a$} 	& Energy     		& $\lambda_{{\rm exc}}^b$	& $\lambda_{{\rm obs}}^c$ 	& \multicolumn{1}{c}{Lifetime}	\\
          			& (cm$^{-1}$)	   	& (\AA)             	& (\AA)            	& \multicolumn{1}{c}{(ns)}				      	\\
\hline
\parent{7}{S}6p z\ls{8}{P}{7/2}	&39~389.49	 	& 2538.0            	& 3173.9	   	& 68(5)				\\
\parent{5}{D}6p z\ls{6}{D}{7/2}	&43~802.36		& 2282.3		& 2486.2		& 5.9(5)				\\
\parent{5}{D}6p z\ls{6}{D}{3/2}	&46~157.19		& 2367.4		& 3479.3		& 5.6(5)				\\
\parent{5}{D}6p z\ls{6}{D}{5/2}	&46~373.51		& 2336.8		& 2879.4		& 5.6(5)				\\
\parent{5}{D}6p z\ls{6}{D}{1/2}	&48~128.08		& 2350.2		& 2409.4		& 5.9(5)				\\
\parent{5}{D}6p z\ls{6}{F}{5/2}	&48~798.70		& 2314.2		& 3202.1		& 6.7(5)				\\
\parent{5}{D}6p z\ls{6}{F}{9/2}	&51~951.61		& 2067.2		& 2580.0		& 3.2(3)				\\
\parent{5}{D}6p z\ls{6}{F}{7/2}	&52~206.48		& 2070.7		& 2453.5		& 4.7(4)				\\
\hline
\end{tabular}}
\medskip
$^a$ Level notation from \citet{Kleef61}. \\
$^b$ Laser wavelength used to populate the upper state. \\
$^c$ Wavelength used to detect the fluorescence signal. 
\end{table}