SIMBAD references

The recent introduction of high-resolution/large spectral-range spectrographs has provided the opportunity to investigate the chemical composition of classical Cepheids in detail. This paper focusses on new abundance determinations for iron and 6 light metals (O, Na, Mg, Al, Si, Ca) in 30 Galactic Cepheids. We also give a new estimate of the Galactic radial abundance gradient. The stellar effective temperatures were determined using the method of line depth ratios, and the surface gravity and the microturbulent velocity v_t by imposing the ionization balance between Fe I and Fe II with the help of curves of growth. Abundances were calculated with classical LTE atmosphere models. Abundances were obtained with rms accuracies of about 0.05-0.10dex for Fe, and 0.05-0.20dex for the other elements. Cepheids in our sample have solar-like abundances, and current measurements agree quite well with previous determinations. We computed ``single zone'' Galactic radial abundance gradients for the 8-12kpc region and found a slope for iron of -0.061dex/kpc.