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.

Bio: Dr.Hui Dong finished his undergraduate study in University of Science and Technology of China with Professor Fuzhen Chen on 2004. Then he moved to University of Massachusetts, Amherst and worked with Professor Daniel Wang on Galactic Center. After that, he began his first postdoc with Dr. Tod Lauer, Abey Saha, Knut Olson and worked with the Panchromatic Hubble Treasury Survey team on the M31 bulge on 2011. He relocated to IAA-CSIC, Spain and worked with the Dr. Rainer Schoedel on the Galactic Center on 2014. His main research interest is nuclear star cluster, extinction law, time domain study and stellar population.