The national Science and Technology Award Conference was hold in Beijing on November 3 2021. Prof. WU Yuanwei from NTSC won the National Prize for Natural in Sciences (second class). This award is offer to the joint research "Investigating on the Spiral Structure of the Milky Way with High Accuracy Maser Astrometry”, conducted by Prof. XU Ye, LI Jingjing, ZHANG Bo, WU yuanwei from the Chinese Academy of Sciences , and ZHENG Xingwu from Nanjing University.

Explorations on the Milky Way are almost in parallel with the development of the Modern astronomy. From the time of William Herschel, it has been passing for more than two hundred years. Astronomers from all over the world have invented various methods to reveal the mystery of the Milky Way. WU Yuanwei (NTSC) together with Prof. XU Ye, LI Jingjing (Purple Mountain Observatory), Zhang Bo (Shanghai Observatory), ZHENG Xing-Wu (Nanjing University) and their BeSSeL international research team (including more than 20 researchers from American, Germany, Italy, Japan, Poland, Netherlands and Korea) used around 20 years and redefined the spiral structure of the Milky Way Galaxy by measuring parallaxes and proper motions of more than 200 interstellar masers. The Milky Way is definitely a giant barred spiral galaxy, with a central bar and four major arms. While, the Local Arm, where we located, appears to be an isolated segment, that extends at least 26000 light-years long, much longer than our previously thought.

The technology they used is called the Very Long Baseline Interforemetry (VLBI), which can achieve extremely high position accuracy of celestial objects by synthesizing telescopes separated by thousands of kilometers in different continents.

Milky Way (Credit: Xing-Wu Zheng & Mark Reid BeSSeL/NJU/CFA)

For more related links:
High resolution phtographs of the Milky Way
https://astronomy.nju.edu.cn/xtzl/
BeSSeL Project
http://www3.mpifr-bonn.mpg.de/staff/abrunthaler/BeSSeL/index.shtml