AsianScientist (Feb. 20, 2018) – Dr. Yoshihide Kozai, the founding Director General of the National Astronomical Observatory of Japan (NAOJ) and former President of the International Astronomical Union (IAU), passed away at the age of 89 in Tokyo on 5 February 2018. During his illustrious career, he specialized in celestial mechanics applied to satellites—natural or artificial—and was a member of the Division on Dynamical Astronomy (DDA) of the American Astronomical Society (AAS).
Kozai’s early career coincided with the exciting era of space exploration when it was literally taking off. One of his prominent works conducted during his stay in the United States from 1958 to 1963 is included in the AAS’s centennial Issue, a special edition of the Astrophysical Journal published in 1999. He enabled the precise forecast of the orbital motion of artificial satellites around the Earth.
The current generation might be familiar with the Kozai mechanism (often called the Kozai-Lidov mechanism), which can explain the migration of giant planets into the proximity of their host stars. Its original application was for the moons of Saturn, and it is applicable to exoplanetary systems.
After his return to Japan, Kozai promoted celestial mechanics research at the Tokyo Astronomical Observatory (TAO) while he was affiliated with the University of Tokyo. He later became its Director General in 1981 and led the conversion of TAO into a national institution by integrating other institutions, thus forming the NAOJ.
He continued as the first Director General of NAOJ until 1994. Faced with the daunting task of promoting world-class research at NAOJ and in Japan, he established or initiated advanced observational facilities (for example, the Subaru Telescope and the Atacama Large Millimeter/submillimeter Array, or ALMA) and high-performance computing facilities.
“Kozai wanted his fellow astronomers in Japan to engage and solve the fundamental problems of the universe by utilizing these facilities. We, the current generation, owe much to him,” said Dr. Masahiko Hayashi, the current Director General of NAOJ.
Kozai’s work was not confined to Japan. He served as President of the IAU from 1988 to 1991 and was the first Japanese to hold that position. For his long years of research and education, the AAS DDA honored him with its Brouwer Award in 1990.
“The community mourns this tremendous loss of a shining star from this world. The only encouraging thought is that his legacy is well alive in the hearts of many,” said Dr. Kazunari Shibata, the current president of the Astronomical Society of Japan .
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Source: National Astronomical Observatory of Japan; Photo: Gunma Astronomical Observatory
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