The Gaia -ESO Survey : No sign of multiple stellar populations in open clusters from their sodium and oxygen abundances
Context. The light element (anti-)correlations shown by globular clusters (GCs) are the main spectroscopic signature of multiple stellar populations. These internal abundance variations provide us with fundamental constraints on the formation mechanism of stellar clusters. Aims. Using Gaia-ESO, the largest and most homogeneous survey of open clusters (OCs), we intend to check whether these stellar
