+ Minor planets discovered: 19 see
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.小石川正弘さん死去 仙台市天文台元職員 星空の魅力伝える
List of discovered minor planets
3994 Ayashi 2 December 1988 4292 Aoba 4 November 1989 4407 Taihaku 13 October 1988 4539 Miyagino 8 November 1988 4871 Riverside 24 November 1989 5128 Wakabayashi 30 March 1989 5751 Zao 5 January 1992 6089 Izumi 5 January 1989 6190 Rennes 8 October 1989 6349 Acapulco 8 February 1995 6859 Datemasamune 13 February 1991 7485 Changchun 4 December 1994 7816 Hanoi 18 December 1987 8084 Dallas 6 February 1989 10500 Nishi-koen 3 April 1987 11514 Tsunenaga 13 February 1991 12252 Gwangju 8 November 1988 14032 Mego 4 December 1994 30963 Mount Banzan 29 November 1994
See also
References