1. Institute of Astronomy, Russian Academy of Sciences, Pyatnitskaya str 48, 119017 Moscow, Russia
2. Department of Astrophysics, University of Vienna, A-1180 Vienna, Austria
3. Research Institute of Physics, Southern Federal University, Rostov-on-Don 344090, Russia
4. Lavrentiev Institute of Hydrodynamics, Siberian Branch of Russian Academy of Sciences, Lavrentieva ave. 15, 630090 Novosibirsk, Russia
5. Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia