Our colleague, Academician Frank H. S. Shu, passed away on April 22, 2023, at home in Atherton, CA, USA. He was 79 years old.

He was born in Kunming, China, in 1943, and emigrated to the U.S. with his family at age 5. He graduated from M.I.T in 1963 and obtained his Ph.D. from Harvard in 1968. After a brief period at Stony Brook University, Shu joined the faculty at the University of California, Berkeley, in 1973. A University Professor Emeritus at the University of California, Berkeley, and University of California, San Diego, Shu was best known for proposing the density wave theory with his Ph.D. advisor C.C. Lin, to explain the structure of spiral galaxies and for initiating a new paradigm of star formation in molecular clouds. He also made important contributions in the areas of close binary star systems, the origin of meteoritic building blocks in the solar system, and spiral structure in planetary rings. Most recently, Shu focused his efforts on issues related to climate changes and developed new concepts using molten salt technology to process waste biomass into biocarbon products and designs for nuclear reactors.

As an educator, Shu mentored a large number of graduate students who have gone on to successful careers in astronomy and related fields. His introductory textbook, The Physical Universe, and graduate-level textbook Physics of Astrophysics have become classics. Shu served as chair of the Astronomy Department at U. C. Berkeley, chair of the Center for Astrophysics and Space Sciences at U.C. San Diego, preparation-committee chair for the establishment of the Institute of Astronomy and Astrophysics Academia Sinica, president of the American Astronomical Society, president of National Tsing Hua University in Hsinchu, Taiwan, and senior fellow of the Hong Kong Institute for Advanced Study at the City University of Hong Kong.

For his contributions, Shu was elected to the American Academy of Arts and Sciences, U.S. National Academy of Science, American Philosophical Society, and Academia Sinica, and has received many awards, including the Helen B. Warner Prize for astronomy, the Brouwer Award in dynamical astronomy, the Dannie Heineman prize in astrophysics, and the Henry Norris Russell lectureship, from the American Astronomical Society, the Shaw prize in astronomy, and the Bruce Medal from the Astronomical Society of the Pacific.