Colloquium on Nov. 2, 2023

Measure distances based on periodic variable stars

Speaker: Xiaodian Chen (NAOC)

Venue: SWIFAR Building 2111

Time: 15:00 PM, Thursday, Nov. 2, 2023

Abstract:

The number of periodic variable stars has increased by 3 million in the last five years, and they play an important role in studying the structure of the Milky Way and measuring distance to galaxies. In this talk, I will present a sample of 800,000 periodic variable stars that we have discovered. With the help of this sample, we presented a 3D intuitive map of the Milky Way disk by using Cepheid stars and found that the stellar disk is warped. We also established the most accurate distance measurement method for old galaxies based on double-mode RR Lyrae stars. With the future telescopes in Lenghu site and the CSST, millions of variable stars in the Local Group will be discovered. They help to study the structure of the Local Group and improve the Hubble constant.

Report PPT:  SWIFAR_Xiaodian Chen.pptx