This is the "Phoenix Cloud" image (file photo). Xinhua News Agency (photo courtesy of Zijinshan Observatory)

　　Xinhua News Agency, Nanjing, April 29 (Reporter Wang Juefan) The reporter learned from the Zijinshan Observatory of the Chinese Academy of Sciences on the 29th that the station’s "Galactic Picture Scroll" sky survey program has released another important achievement. The scientific research team discovered two huge molecular clouds that harbor stars in the Milky Way. Researchers named them "River Cloud" and "Phoenix Cloud" respectively.

　　The Milky Way galaxy we live in is a spiral galaxy. Near its spiral arms are some thick clouds, some of which are mainly composed of hydrogen gas molecules, which are molecular clouds. As the molecular clouds continue to collapse, the pressure increases and the temperature rises, and gradually a protostar embryo is formed. When the nuclear fusion energy in the protostar embryo is enough to resist its own attractive forces, a new star is born. Therefore, molecular clouds are the precursors of stars and are called "stellar cradles".

　　The "Dajiang Molecular Cloud" and "Phoenix Molecular Cloud" discovered this time are located in the Great Rift Valley region of the Aquila constellation. Among them, the "Dajiang Molecular Cloud" is about 1,300 light-years away from the solar system. In form, it looks like a long river winding in the universe, and the actual length is about 300 light-years. The "Phoenix Molecular Cloud" is more like a large bird with wings. It is about 2,000 light-years away from the solar system and has about 200,000 times the mass of the sun. "Dajiang" and "Phoenix" are both "big heads" in the Milky Way.

　　This is the image of "River Cloud" (file photo). Posted by Xinhua News Agency (photo courtesy of Zijinshan Observatory)

　　"What’s even more exciting is that we can see direct evidence of star formation in the Great River, and stars are probably forming in the Phoenix," said Su Yang, an associate researcher at the Purple Mountain Observatory who worked on the study.

　　Yang Ji, the head of the "Galaxy Picture Scroll" sky survey program and a researcher at the Purple Mountain Observatory, introduced that the "Galaxy Picture Scroll" sky survey program mainly observes the area of ± 5 on the northern galactic plane, with a total observation range of 2,600 square degrees. The program started in 2011 and is led by the Purple Mountain Observatory, completing observations of about 250 square degrees every year. The "Galaxy Picture Scroll" will achieve many scientific goals such as discovering and compiling molecular cloud source tables for all regions, and analyzing the physical and chemical properties of molecular clouds. These studies are of great significance to human understanding of the origin of stars, planets, and the entire galaxy.

　　"At present, the’Galactic Picture Scroll ‘has completed 80% of the observation plan, and dozens of important results have been released. It is expected that all observations will be completed in about three years. By then, we will have an unprecedented image of the Milky Way, and people’s understanding of the Milky Way will be greatly expanded." Yang Ji said.

　　The research results were recently published in the Astrophysical Journal, an authoritative journal of astronomy.