1. Institute of Continuous Media Mechanics, Korolyov str. 1, 614013 Perm, Russia
2. Crimean Astrophysical Observatory RAS, Nauchny 298409, Crimea
3. Sternberg State Astronomical Institute, Lomonosov Moscow State University, Moscow 119991, Russia
4. IZMIRAN, Kaluzhskoe shosse, 4, Troitsk, Moscow 142191, Russia
5. Department of Physics, Moscow State University, Moscow 119991, Russia
6. Moscow Center of Fundamental and Applied Mathematics, Moscow 1199991, Russia