Lunch talk on Sep. 28, 2020

Reference Frames in the era of Gaia

Speaker: Niu Liu（Nanjing University）

Venue: Video conference

Time: 12:30 PM, Monday, Sep. 28, 2020

Abstract: 

The celestial frame serves as the fundamental coordinate system for positioning in the astrometry, geodesy, and space navigation. In the past twenty years, the celestial frame, namely the International Celestial Reference Frame (ICRF), is materialized by the observations from the very long baseline interferometry (VLBI) at an accuracy of several tens of micro-arcsecond. Recently, the data releases from ESA’s Gaia mission bring us an opportunity of constructing a multi-wavelength micro-arcsecond reference frame. I will first introduce the concept of the reference system and reference frame. Then I will review the celestial frames used in history. Several examples will be given to illustrate how a high-accuracy reference frame benefits studies in astrophysics and geoscience. In the end, I will talk about contributions from Gaia to the reference frame and astrometry.