National Astronomical Observatories/Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China;
Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650011 China;
Graduate University of Chinese Academy of Sciences Beijing 100049 China;
National Astronomical Observatories/Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China;
Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650011 China;