1. Department of Physics and Earth Science of the University of Ferrara, Via Saragat 1, I-44122 Ferrara, Italy
2. INAF – Astronomical Observatory of Capodimonte, via Moiariello 16, I-80131 Napoli, Italy
3. Department of Physics ‘E. Pancini’, University of Naples Federico II, via Cinthia 21, I-80126 Napoli, Italy
4. INFN – Napoli Unit, via Cinthia 21, I-80126 Napoli, Italy
5. Department of Astronomy, California Institute of Technology, Pasadena, CA 90125, USA
6. INAF – Astronomical Observatory of Abruzzo, Via Mentore Maggini snc, Loc. Collurania, I-64100 Teramo, Italy
7. Center for Astrophysics | Harvard & Smithsonian, 60 Garden St, Cambridge, MA 02138, USA
8. Institute of Astrophysics, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago, Chile
9. European Southern Observatory, Karl-Schwarzschild-Str 2, D-85748 Garching, Germany
10. European Southern Observatory, Alonso de Cordova 3107, 7630355 Vitacura, Santiago, Chile
11. School of Physics and Astronomy, Sun Yat-sen University, Zhuhai Campus, Guangzhou 519082, P.R. China
12. Kapteyn Astronomical Institute, University of Groningen, PO Box 800, NL-9700 AV Groningen, the Netherlands