was a Japanese astronomer. He studied both major and minor planets, and discovered multiple asteroids. Koishikawa was a staff member of the Sendai Astronomical Observatory frin 1972. His research was based out of the Sendai's Ayashi (391) station. The main-belt asteroid 6097 Koishikawa, discovered by Kin Endate and Kazuro Watanabe at Kitami in 1991, was named in his honor. He died on 26 August 2020 from lung cancer. List of discovered minor planets See also References 1952 births 2020 deaths Deaths from lung cancer Discoverers of asteroids 20th-century Japanese astronomers