1. Padua Astronomical Observatory National Institute for Astrophysics (INAF) Padua Italy
2. Astronomical Observatory Belgrade Serbia
3. Department of Physics and Astronomy “Galileo Galilei” University of Padua Padua Italy
4. ICRA, Physics Department University La Sapienza Rome Italy
5. Nicolaus Copernicus Astronomical Center Polish Academy of Sciences Warsaw Poland
6. Center for Theoretical Physics Polish Academy of Sciences Warsaw Poland
7. Instituto de Astrofísica de Andalucía, CSIC Granada Spain
8. Instituto de Astronomía, UNAM Mexico