STELLAR COMPOSITIONS FROM NARROW-BAND PHOTOMETRY .1. IRON ABUNDANCES IN 180 G AND K GIANTS

Using narrow-band indices observed with the Cambridge spectrophotometer, red-infra-red colours, and independent luminosity estimates, the iron abundances of 180 G and K type giant stars have been determined. The indices were analysed using synthetic spectra computed from model atmospheres. The estimated uncertainties in [Fe/H] vary from 0.2 in metal-rich stars to 0.3 in metal-poor stars. A comparison with the results of detailed spectroscopic analyses by other authors yields a r.m.s. difference of only 0.13 in [Fe/H]. The abundances of a number of the possible members of the Hyades, Pleiades, Wolf 630, ζ Herculis, σ Puppis, 61 Cygni, η Cephei and γ Leonis moving stellar groups are discussed. While most of the probable members of the Hyades group observed have iron abundances, [Fe/H] = 0.2, close to that of the cluster giants, most of the other groups are less homogeneous and contain more interlopers. The 'old' group and high-velocity stars show a broad abundance distribution from metal-poor to super-metalrich. © 1971 Royal Astronomical Society. Provided by the NASA Astrophysics Data System.