2000A&A...362..563T

Using both high-dispersion and low-resolution data, the metallicities of nine old moving groups and superclusters are analyzed. These stellar groupings include the HR 1614 and Hyades superclusters and the Wolf 630, ζ Her, 61 Cyg, HR 1614, σ Pup, η Cep, and Arcturus groups. Samples of these stellar groupings are drawn from Eggen's membership lists. Precautions are taken against problems posed by reddening, visual and spectroscopic binaries, and typographical errors in Eggen's lists. When required, the analyses allow for systematic differences between low-resolution and high-dispersion metallicities. It is found that none of the stellar groupings have the small metallicity dispersion found for a selection of galactic clusters. Instead, the metallicity dispersions turn out to be comparable to the dispersion for a random selection of field stars. For most of the stellar groupings, it does not seem possible at present to learn more by analyzing metallicities. However, one can be more definite about three of them: the HR 1614 supercluster, the HR 1614 group, and the Hyades supercluster. Using a membership list from Eggen (1998AJ....115.2453E) that is based on Hipparcos astrometry, no evidence is found for the existence of an HR 1614 supercluster. To isolate an HR 1614 group, results from a kinematic analysis (Dehnen, 1998AJ....115.2384D) are then used to select a tentative list of members from Eggen's group and supercluster lists. From the mean metallicity of the redefined group, it is found that the group is very unlikely to be a random, magnitude-limited sample of stars. A similar result is obtained for a version of the Hyades supercluster derived from 18 of Eggen's membership lists. About 43% of the stars in this version turn out to be members of the supercluster.