Place: Middle Conference Room (中会议室) 

　　Date & Time: 10:00am on Oct. 12th (Wednesday) 

　　Speaker: Hui DONG (Instituto de Astrofísica de Andalucía - CSIC, Spain) 

　　Title: Time Domain Study in the central 5 pc of the Milky Way's Central Black Hole 

　　Abstract: Nuclear star clusters have been found in 75\% of local spiral galaxies. They are very compact and massive and seem to co-evolve with central massive black holes. Their origins are still not very clear. Due to its proximity, the Milky Way nuclear star cluster (MWNSC) is a unique lab to study its stellar populations and star formation histories, which help us to understand how MWNSC formed. However, the sample of previous spectrography observations is small. High and extreme spatial variable extinctions limit the use of color magnitude diagram. Instead, we present a time domain study for the central 5 pc of the Milky Way with a four-year baseline HST/WFC3 observations at the F153M (1.53 micron) band. I will give a comprehensive description of the stellar types and variability types of variable stars detected in our catalog and discuss how they can impact our understanding of the stellar populations and then the origin of Milky Way nuclear star cluster. The time domain study of the MWNSC could be an important scientific case for the future Chinese 12 m telescope with large field-of-view.