Chemical abundances in the outer disk clusters Tombaugh 2, Melotte 71, and NGC 2112

We have analyzed high-dispersion echelle spectra of two or three stars each in the old anticenter disk clusters Tombaugh 2, NGC 2112, and Melotte 71. We find all three clusters to be mildly metal deficient, with [Fe/H]similar or equal to-0.45, -0.1, and -0.3, respectively, with an error of similar to 0.2 dex. The clusters also have slight overdeficiencies of oxygen and nearly solar proportions of the ct elements, indicating a lower relative contribution by massive stars to the chemical evolution of the outer Galactic disk. The clusters are found to be less metal deficient than photometric and low-resolution spectroscopic studies had indicated, which we attribute to severe nonmember contamination in those samples and/or reddening uncertainties. Our analysis suggests reddening values of E(B - V)=0.3-0.3 for Tom 2 and E(B - V)approximate to 0.6 for NGC 2112. NGC 2112 suffers from severe field star contamination. (C) 1996 American Astronomical Society.