All Figures

$\begin{figure} \par {\includegraphics[width=8.8cm,clip]{H4751_f1.eps} }\end{figure}$ Figure 1: 2MASS CMDs for the Pleiades (M 45) built with WEBDA parameters and Padova isochrones. Left panel: $M_J \times (J - H) _0$ ; right panel: $M_{K_{\rm S}} \times (J-K_{\rm S})_0$ . The loci of solar vicinity MS (dashed-line) and Giant (dotted line) stars are also indicated as reference. Age and metallicity refer to the isochrone used. Notice that the Padova isochrone colours correspond to the Johnson photometry.
Open with DEXTER

In the text

$\begin{figure} \par {\includegraphics[width=8.5cm,clip]{H4751_f2.eps} }\end{figure}$ Figure 2: Same as Fig. 1 for M 41 (NGC 2287).
Open with DEXTER

In the text

$\begin{figure} \par {\includegraphics[width=8.5cm,clip]{H4751_f3.eps} }\end{figure}$ Figure 3: Same as Fig. 1 for Praesepe (NGC 2632).
Open with DEXTER

In the text

$\begin{figure} \par {\includegraphics[width=8.5cm,clip]{H4751_f4.eps} }\end{figure}$ Figure 4: Same as Fig. 1 for M 67 (NGC 2682).
Open with DEXTER

In the text

$\begin{figure} \par {\includegraphics[width=8.5cm,clip]{H4751_f5.eps} }\par\end{figure}$ Figure 5: Same as Fig. 1 for NGC 6791. With respect to the WEBDA distance modulus, we needed to apply an additional correction of $\Delta (m-M)=+0.8$ to the stars for both magnitude axes in order to reconcile observation and isochrone.
Open with DEXTER

In the text

$\begin{figure} \par {\includegraphics[width=8.8cm,clip]{H4751_f6.eps} }\end{figure}$ Figure 6: A best-fit for M 67 is obtained with somewhat older isochrones (with respect to WEBDA's data) which, however, do not fix the MS and giant branch deviations. Left panel: $M_J \times (J - H) _0$ ; right panel: $M_{K_{\rm S}} \times (J-K_{\rm S})_0$ .
Open with DEXTER

In the text

$\begin{figure} \par {\includegraphics[width=8.8cm,clip]{H4751_f7.eps} }\end{figure}$ Figure 7: 2MASS J, H and $K_{\rm S}$ transmission curves ( middle panel) are compared to those of the Johnson system ( top panel); spectra of representative stars are shown in the bottom panel.
Open with DEXTER

In the text

$\begin{figure} \par {\includegraphics[width=8.8cm,clip]{H4751_f8.eps} }\end{figure}$ Figure 8: Comparison of Johnson K with 2MASS $K_{\rm S}$ isochrones for different ages and solar metallicity. Insets show blowups of the turnoff and giant branch regions of the 10 Gyr isochrone. Differences ( $K-K_{\rm S}$ ) are $\approx$ +0.02 at the turnoff and $\approx$ -0.01 at the giant branch.
Open with DEXTER

In the text

$\begin{figure} \par {\includegraphics[width=8.8cm,clip]{H4751_f9.eps} }\end{figure}$ Figure 9: Same as Fig. 8 for the J and H filters. Differences in (J-H)₀ colour are at most 0.01 throughout.
Open with DEXTER

In the text

$\begin{figure} \par {\includegraphics[width=8.5cm,clip]{H4751_f2.eps} }\end{figure}$	Figure 2: Same as Fig. 1 for M 41 (NGC 2287).
Open with DEXTER

$\begin{figure} \par {\includegraphics[width=8.5cm,clip]{H4751_f3.eps} }\end{figure}$	Figure 3: Same as Fig. 1 for Praesepe (NGC 2632).
Open with DEXTER

$\begin{figure} \par {\includegraphics[width=8.5cm,clip]{H4751_f4.eps} }\end{figure}$	Figure 4: Same as Fig. 1 for M 67 (NGC 2682).
Open with DEXTER

$\begin{figure} \par {\includegraphics[width=8.5cm,clip]{H4751_f5.eps} }\par\end{figure}$	Figure 5: Same as Fig. 1 for NGC 6791. With respect to the WEBDA distance modulus, we needed to apply an additional correction of $\Delta (m-M)=+0.8$ to the stars for both magnitude axes in order to reconcile observation and isochrone.
Open with DEXTER

$\begin{figure} \par {\includegraphics[width=8.8cm,clip]{H4751_f6.eps} }\end{figure}$	Figure 6: A best-fit for M 67 is obtained with somewhat older isochrones (with respect to WEBDA's data) which, however, do not fix the MS and giant branch deviations. Left panel: $M_J \times (J - H) _0$ ; right panel: $M_{K_{\rm S}} \times (J-K_{\rm S})_0$ .
Open with DEXTER

$\begin{figure} \par {\includegraphics[width=8.8cm,clip]{H4751_f7.eps} }\end{figure}$	Figure 7: 2MASS J, H and $K_{\rm S}$ transmission curves ( middle panel) are compared to those of the Johnson system ( top panel); spectra of representative stars are shown in the bottom panel.
Open with DEXTER

$\begin{figure} \par {\includegraphics[width=8.8cm,clip]{H4751_f8.eps} }\end{figure}$	Figure 8: Comparison of Johnson K with 2MASS $K_{\rm S}$ isochrones for different ages and solar metallicity. Insets show blowups of the turnoff and giant branch regions of the 10 Gyr isochrone. Differences ( $K-K_{\rm S}$ ) are $\approx$ +0.02 at the turnoff and $\approx$ -0.01 at the giant branch.
Open with DEXTER

$\begin{figure} \par {\includegraphics[width=8.8cm,clip]{H4751_f9.eps} }\end{figure}$	Figure 9: Same as Fig. 8 for the J and H filters. Differences in (J-H)₀ colour are at most 0.01 throughout.
Open with DEXTER