1. Physics Department and Tsinghua Center for Astrophysics, Tsinghua University , Beijing 100084, China
2. Beijing Planetarium, Beijing Academy of Science and Technology , Beijing 100044, China
3. The School of Physics and Astronomy, Tel Aviv University , Tel Aviv 69978, Israel
4. Yunnan Observatories, Chinese Academy of Sciences , Kunming 650216, China
5. Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences , Kunming 650216, China
6. Center for Astronomical Mega-Science, Chinese Academy of Sciences , 20A Datun Road, Chaoyang District, Beijing 100012, China
7. Department of Astronomy, University of California , Berkeley, CA 94720-3411, USA
8. Ulugh Beg Astronomical Institute, Uzbekistan Academy of Sciences , Tashkent 100052, Uzbekistan
9. Department of Astronomy and Astrophysics, Physics Faculty, National University of Uzbekistan , Tashkent 100174, Uzbekistan
10. Department of Astronomy, Beijing Normal University , Beijing 100875, China