S. Molkov (1), A. Lutovinov (1,2), S. Tsygankov (3,1), I. Mereminskiy (1), A. Mushtukov (4,1,5) (1 - Space Research Institute, Russia, 2 - Moscow Institute of Physics, Technology, Russia, 3 - University of Turku, Finland, 4 - Leiden Observatory, Leiden University, The Netherlands, 5 - Pulkovo Observatory, Russia)
