【T. D. Lee Colloquium No.28】Searching for the very massive first stars
by
Tsung-Dao Lee Institute/S5F-S500 - Lecture Hall
Tsung-Dao Lee Institute
Tencent meeting link: https://meeting.tencent.com/dm/3qQEH58qD0Af (meeting ID: 641 323 922 no password)
Host：Prof. Jie Zhang （张杰）
Abstract:
Theoretical studies suggest that the first-generation stars formed in the early universe could reach masses of several hundred to over a thousand solar masses. However, such massive stars have never been observed. An international research team led by the National Astronomical Observatories identified a low-alpha star with peculiar chemical abundances in the Galactic halo, using data from the LAMOST spectroscopic survey. High-resolution spectroscopic observations conducted with Japan’s 8.2-meter Subaru Telescope revealed that the star’s elemental abundance pattern is consistent with theoretical models of pair-instability supernovae. Detailed analysis indicates that the material forming this star primarily originated from a first-generation very massive star with a mass of about 260 solar masses. This discovery provides unprecedented observational evidence that the first stars could reach several hundred solar masses and demonstrates the key role of pair-instability supernovae in the early chemical evolution of the universe，holding significant scientific value for studying the origin of elements, star formation, and galactic chemical evolution in the early universe.
Bio:
Gang ZHAO is Academician of the Chinese Academy of Sciences (CAS) and Professor at the National Astronomical Observatories, CAS. He currently serves as the Chair of the LAMOST Science Committee. He has received numerous prestigious awards, including the China Youth Scientist Award, the Science and Technology Progress Award of Ho Leung Ho Lee Foundation, and the CAS Outstanding Science and Technology Achievement Prize etc. He is currently the principal investigator of the Excellence Research Project of the National Natural Science Foundation of China. Prof. Zhao’s research fields are related to the stellar spectroscopic analysis, exoplanets, the formation and evolution of the Milky Way, and laboratory astrophysics. His work has been recognized many times as China's Top Ten Astronomical Advances of the Year. His research on exploring the chemical evolution of the Milky Way through stellar abundances was honored with the Second Prize of the National Natural Science Award.
