A statistical search for supermetallicity in F, G and K stars

High-dispersion and low-resolution data are combined to search for super-metal-rich (SMR) FGK stars in the solar neighbourhood and Baade's Window. The data are assessed by using statistical analysis, with their rms errors playing a key role. A star is considered to be SMR if its value of [Fe/H] > +0.2 dex, while 'borderline' SMR status may be assigned if +0.1 < [Fe/H] ≤ +0.2 dex. Borderline SMR status is assigned to μ Leo and three other giants, but no full-fledged SMR giants are found in either Baade's Window or the solar neighbourhood. By contrast, the existence of SMR class IV-V stars turns out to be well established, with values found for [Fe/H] that are as large as ∼ +0.4 dex. It is concluded that this apparent contrast between class IV-V stars and giants should not be interpreted in astrophysical terms at present because of marked shortcomings in the available data base for giants. Recommendations are made about future research that may cure this problem and extend present knowledge about SMR dwarfs.