Abundance of α-elements in red clump giants

Based on high-resolution, high signal-to-noise ratio spectra, we have analysed the abundance of five α elements (Mg, Si, S, Ca, Ti) in 17 red clump giants. The results show that the giants can be divided into two categories, one metal-rich, with metallicity [Fe/H]≥ 0.0, the other metal-poor, with [Fe/H]≤ −0.3. The abundances of the five elements in both categories increase with increasing metallicity. The results indicate that, for both categories, the nucleosynthesis and the evolution of iron and the five elements are probably in step.