Affiliation: | (1) Astronomical Observatory, St. Petersburg, Russia;(2) State University, St. Petersburg, Russia;(3) Inter-University Centre for Astronomy and Astrophysics, Pune, India;(4) Physical Research Laboratory, Ahmedabad, India;(5) Department of Applied Mathematics, Russian State Pedagogical University, St. Petersburg, Russia;(6) Inter-University Centre for Astronomy and Astrophysics, Pune, India;(7) Institute of Astronomy, Cambridge, UK |