1. Instituto de Astronomía, Universidad Nacional Autónoma de México , AP 106, Ensenada 22800, BC, México
2. Faculty of Mathematics and Physics, Astronomical Institute, Charles University , V Holešovičkách 2, CZ-180 00 Praha 8, Czech Republic
3. Faculty of Physics and Technology, Al-Farabi Kazakh National University , Al-Farabi Ave. 71, Almaty 050040, Kazakhstan