Carbon and iron abundances for twenty F and G type stars.

Summary. Carbon and iron abundances are presented for twenty dwarfs and subgiants of spectral type about F 6 to K 0, as an extension of a program of differential fine analysis of the CH and Fe I spectra in disk stars. The results for the overall total of fity stars are discussed, and the general trend of [C/H] -32[Fe/H], which was reported earlier, is confirmed. The possibility is briefly discussed that the evidence implies a change with time in the abundance distribution of the elements in the yield of newly-forming heavy elements which enrich the interstellar medium. The relation found between carbon and iron abundances implies a larger proportion of low-Z stars than would be deduced on the basis of [Fe/H] alone, and this largely resolves the well-known problem of the dearth of low-abundance stars relative to the predicted numbers. Key words: carbon and iron abundances - solar-type dwarfs - subgiants - numbers of low-abundance stars