1. INAF—Osservatorio Astronomico di Padova, Padova, Italy
2. Johannes Kepler University Linz, Industrial Mathematics Institute, Linz, Austria
3. INAF—Osservatorio Astronomico d’Abruzzo, Teramo, Italy
4. INAF—Osservatorio Astrofisico di Arcetri, Firenze, Italy
5. MPE—Max-Planck-Institut für extraterrestrische Physik Giessenbachstrasse 1, Garching, Germany
6. LUT University, Lappeenranta, Finland
7. INAF—Osservatorio Astronomico di Roma, Monte Porzio Catone, Italy