\begin{table}%t2 \caption{\label{t:obs}List of observations and measured CH and \CHP\ equivalent widths (in m\AA; uncertainties as estimated in Sect. 3.2.1 are given in upper index).} %\centerline {\begin{tabular}{cccccccc} \hline\hline Epoch & Observatory & $R^a$ & $W_{4300}$(CH) [m\AA]& $W_{4232}$(CH$^+$)& $W_{4300}$(CH)& $N$(CH)$^c$& $N$(\CHP)$^c$\\ & & & \multicolumn{2}{c}{HD~34078}& \zper& \multicolumn{2}{c}{HD~34078} \\ \hline\noalign{\smallskip} 2002.73& & & $57.35^{0.92}$ & $47.30^{1.51}$ & --- & $0.97^{0.02}$ & $0.69^{0.02}$\\ 2003.15& & & $54.06^{0.76}$ & $44.50^{1.19}$ & $15.05^{0.39}$ & $0.89^{0.01}$& $0.63^{0.02}$\\ 2003.71& & & $52.36^{0.93}$ & $46.44^{1.30}$ &$16.22^{0.46}$ & $0.85^{0.02}$ & $0.67^{0.02}$\\ 2003.96& & & $55.54^{1.77}$ & ----& $15.26^{0.58}$ & $0.92^{0.03}$&---\\ 2004.15& OHP/ELODIE$^b$ & 32~000 & $51.94^{0.81}$ & $46.66^{1.30}$& $16.22^{0.99}$& $0.84^{0.01}$& $0.67^{0.02}$ \\ 2004.88& & & $54.70^{1.20}$ & ----& ---- & $0.90^{0.02}$&---\\ 2005.72& & & $51.30^{0.90}$ & $45.36^{1.40}$& $15.16^{0.64}$ & $0.82^{0.01}$& $0.65^{0.02}$\\ 2006.11& & & $48.97^{0.95}$ & $42.01^{1.40}$& ---- & $0.77^{0.01}$& $0.58^{0.02}$\\ \hline\noalign{\smallskip} 2006.71& & & $54.91^{0.32}$& $44.23^{0.52}$& $15.98^{0.13}$ & $0.909^{0.005}$& $0.623^{0.007}$\\ 2007.14& OHP/SOPHIE & 75~000 & $51.00^{0.51}$& $41.30^{0.45}$& $16.01^{0.26}$ & $0.815^{0.008}$& $0.563^{0.006}$ \\ 2007.67& & & $53.30^{0.36}$& $45.33^{0.47}$& $16.05^{0.13}$ & $0.869^{0.006}$& $0.646^{0.007}$ \\ 2008.10& & & $54.16^{0.30}$& $48.29^{0.43}$& $16.22^{0.15}$ & $0.890^{0.005}$& $0.710^{0.006}$ \\ \hline\noalign{\smallskip} 2003.00& & & $55.50^{0.28}$& $44.78^{0.45}$& $15.80^{0.14}$ & $0.880^{0.004}$& $0.632^{0.006}$ \\ 2004.02& & & $52.10^{0.32}$& $47.00^{0.51}$& $14.90^{0.36}$ & $0.816^{0.005}$& $0.672^{0.007}$\\ 2004.76& & & $50.80^{0.69}$&----& $15.70^{0.29}$ & $0.816^{0.01}$&---\\ 2004.98& McDonald & 170~000 & $53.10^{0.33}$& $47.30^{0.57}$& $15.70^{0.18}$ & $0.843^{0.005}$& $0.697^{0.008}$\\ 2005.81& & & $49.00^{0.26}$& $44.90^{0.60}$& $16.00^{0.08}$ & $0.763^{0.004}$& $0.636^{0.009}$ \\ 2005.99& & & $49.90^{0.22}$& $43.50^{0.60}$& $16.15^{0.11}$ & $0.774^{0.003}$ & $0.613^{0.008}$\\ 2007.02& & & $53.20^{0.40}$& $42.70^{0.42}$& $15.88^{0.18}$ & $0.832^{0.006}$ & $0.595^{0.006}$ \\ 2008.00& & & $54.34^{1.08}$& $47.88^{1.64}$& $15.74^{0.15}$ & $0.90^{0.02}$ & $0.68^{0.02}$ \\ \hline\noalign{\smallskip} 2004.10& BOAO & 30~000 & $52.50^{0.45}$& ----& --- & $0.850^{0.007}$ & ---\\ 2004.18& BOAO-Terskol & 30~000--120~000 & $50.67^{0.35}$& ----&--- & $0.807^{0.006}$ &---\\ 2006.77& BOAO & 45~000 & $54.60^{0.62}$& $44.40^{0.60}$& --- & $0.90^{0.01}$ & $0.627^{0.008}$ \\ \hline\noalign{\smallskip} 2004.65& Terskol& 120~000& $55.00^{0.45}$& ----& --- & $0.911^{0.007}$ &---\\ \hline\noalign{\smallskip} 2007.18& Calar Alto& 40~000 & $52.15^{0.88}$& $41.80^{0.95}$& --- & $0.84^{0.02}$ & $0.57^{0.01}$ \\ \hline \end{tabular}} \medskip \par $^a$\ Resolution near \CHl. $^b$\ \WCHl\ and \WCHPlb\ values from OHP/ELODIE spectra have been corrected by +6\% and +8\% respectively (see text). $^c$\ Column densities in units of $10^{14}$ \units{cm}{-2}, measured directly from line profiles for high resolution spectra (McDonald) or computed from $W$ values using Eqs.~(1) and~(2) for other data. \end{table}