The Gaia -ESO Survey: Age spread in the star forming region NGC 6530 from the HR diagram and gravity indicators

The authors acknowledge support through the PRIN INAF 2014 funding scheme of the National Institute for Astrophysics (INAF) of the Italian Ministry of Education, University and Research (>The Gaia-ESO Survey>, P.I.: S. Randich). This work was partly supported by the European Union FP7 programme through ERC grant number 320360 and by the Leverhulme Trust through grant RPG-2012-541.