All Tables

• Table 1: The measurements of our sample stars. The names in Col. 1 are taken from Eggen (1969) for NGC 3680, Anthony Twarog et al. (1988) (AMC) and Eggen (1971) for IC 4651, Sanders (1977) for M 67, Klein Wassink (1927) for Praesepe & van Bueren (1952) for the Hyades stars. The photometry is taken from the reference papers for IC 4651, from Nordström et al. (1997) for NGC 3680, from Hipparcos Catalogue (ESA 1997) for Hyades, from Jones & Stauffer (1991) for Praesepe, with the exception of KW 368 which is taken from Jones & Cudworth (1983), and from Montgomery et al. (1993) for M 67. Regarding chromospheric-activity indices measurements, there are the 1-Å indices derived from spectra either non corrected (Col. 4) or corrected (Col. 5) for the absorption of the IS medium. From the corrected index we have subtracted the photospheric contribution, which is 0.049 Å, and transformed the result into flux. The final data are in Col. 6. measurements in Col. 8 are taken from Paulson et al. (2003) for Hyades, for all the other clusters are based on the FWHMs in Col. 7 via the calibrations in Sect. 3.2.
• Table 2: Literature data used for the calibration in Fig. 6. The range of B-V colours is 0.514-0.641, closely encompassing the solar one.
• Table 3: Rotational periods of Hyades from Radick et al. (1987) and rotational velocities from them inferred. The data are collected to compare equatorial with projected rotational velocities.
• Table 4: Peak to peak spread of the fluxes within each cluster, expressed in percentage of the related mean value. The spread of the solar data is the variation during the solar cycle 21.
• Table 5: X-ray flux measurements of Praesepe and Hyades stars. All of them but one refer to the ROSAT detection in the band 0.1-2.0 keV. KW 326 was not detected by ROSAT. Its measurement, which refers to the same band, has been performed with XMM-Newton satellite.