Chemical analysis of giant stars in the young open cluster NGC 3114

Context. Open clusters are very useful targets for examining possibl e trends in galactocentric distance and age, especially whe n young and old open clusters are compared. Aims. We carried out a detailed spectroscopic analysis to derive t he chemical composition of seven red giants in the young open cluster NGC 3114. Abundances of C, N, O, Li, Na, Mg, Al, Ca, Si, Ti, Ni, Cr, Y, Zr, La, Ce, and Nd were obtained, as well as the carbon isotopic ratio. Methods. The atmospheric parameters of the studied stars and their ch emical abundances were determined using high-resolution optical spectroscopy. We employed the local-thermodynamic-equilibrium model atmospheres of Kurucz and the spectral analysis codemoog. The abundances of the light elements were derived using the spectral synthesis technique. Results. We found that NGC 3114 has a mean metallicity of [Fe/H] =−0.01±0.03. The isochrone fit yielded a turn-o ff mass of 4.2 M⊙. The [N/C] ratio is in good agreement with the models predicted by firs t dredge-up. We found that two stars, HD 87479 and HD 304864, have high rotational velocities of 15.0 km s −1 and 11.0 km s −1 ; HD 87526 is a halo star and is not a member of NGC 3114. Conclusions. The carbon and nitrogen abundance in NGC 3114 agree with the fi eld and cluster giants. The oxygen abundance in NGC 3114 is lower compared to the field giants. The [O/Fe] ratio is similar to the giants in young clusters. We detec ted sodium enrichment in the analyzed cluster giants. As far as the othe r elements are concerned, their [X/Fe] ratios follow the same trend seen in giants with the same metallicity.