Physics and Space Science College;
China West Normal University;
Nanchong 637009;
China;
Senior Middle School of Hangzhou;
Hangzhou 310016;
China;
Key Laboratory of Optical Astronomy;
National Astronomical Observatories;
Chinese Academy of Sciences;
Beijing 100101;
China;
University of Chinese Academy of Sciences;
Beijing 100049;
China;
School of Physics and Astronomy;
Sun Yat-sen University;
Zhuhai 519082;
China;
open clusters and associations:individual(NGC 869); stars:variables:general;