1. Crimean Astrophysical Observatory, Nauchny 298409, Republic of Crimea
2. Astronomical Observatory, Odessa National University, Shevchenko Park, UA-65014 Odessa, Ukraine
3. GEPI, Observatoire de Paris, PSL Research University, CNRS, Place Jules Janssen, F-92195 Meudon, France
4. INAF–Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze, Italy