We present new FLAMES @ VLT spectroscopic observations of 30 stars in the field of the LMC stellar cluster NGC 1866 .
NGC 1866 is one of the few young and massive globular cluster that is close enough so that its stars can be individually studied in detail .
Radial velocities have been used to separate stars belonging to the cluster and to the LMC field and the same spectra have been used to derive chemical abundances for a variety of elements , from [ Fe/H ] to the light ( i.e .
Na , O , Mg… ) to the heavy ones .
The average iron abundance of NGC 1866 turns out to be [ Fe/H ] = –0.43 \pm 0.01 dex ( with a dispersion \sigma = 0.04 dex ) , from the analysis of 14 cluster-member stars .
Within our uncertainties , the cluster stars are homogeneous , as far as chemical composition is concerned , independent of the evolutionary status .
The observed cluster stars do not show any sign of the light elements ’ anti-correlation ’ present in all the Galactic globular clusters so far studied , and also found in the old LMC stellar clusters .
A similar lack of anti-correlations has been detected in the massive intermediate-age LMC clusters , indicating a different formation/evolution scenario for the LMC massive clusters younger than \sim 3 Gyr with respect to the old ones . Also opposite to the Galactic globulars , the chemical composition of the older RGB field stars and of the young post-MS cluster stars show robust homogeneity suggesting a quite similar process of chemical evolution .
The field and cluster abundances are in agreement with recent chemical analysis of LMC stars , which show a distinctive chemical pattern for this galaxy with respect to the Milky Way .
We discuss these findings in light of the theoretical scenario of chemical evolution of the LMC .