It is with profound sorrow that we announce the passing of Professor Da-Run Xiong, a distinguished stellar physicist, senior researcher at the Purple Mountain Observatory, and Academician of the Chinese Academy of Sciences. Professor Xiong passed away in Nanjing on March 5, 2026, at the age of 88.

Professor Xiong is best known for "Xiong's theory of turbulent convection", a non-local and time-dependent framework for stellar convection based on hydrodynamic equations and turbulence theory. His work provided a physically motivated alternative to classical local mixing-length treatments, offering critical insights into convection, overshooting, and convection–oscillation coupling. His theory has been applied to a wide range of problems in stellar physics, including structure and evolution of stars, helio- and astero-seismology, anormaly of lithium and other elements in stars. Additionally, his contributions significantly advanced our theoretical understanding of instability strips and the interaction between convection and oscillation in variable stars.

In recognition of his scientific achievements, Professor Xiong received numerous honors, including the First Prize for Natural Science of the Chinese Academy of Sciences, the Second Prize of the State Natural Science Award, the Wang Danping Science and Technology Award, and the Ho Leung Ho Lee Foundation Prize for Scientific and Technological Progress.

Professor Xiong was deeply devoted to the country and the advancement of science and education. He was a scholar of immense dedication who cared deeply about social welfare and the public good. Having devoted his entire life to scientific research, he made outstanding contributions to the development of astrophysics in China. His passing is a tremendous loss to the scientific community. He will be remembered with great respect by colleagues, students, and all those who benefited from his work and spirit.

In accordance with Professor Xiong's wishes, funeral arrangements will be kept simple, and no formal farewell ceremony will be held.

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