was a Japanese astrophysicist. Hayashi tracks on the HertzsprungâÂÂRussell diagram are named after him.
Hayashi was born in Kyoto and enrolled at the Tokyo Imperial University (now the UTokyo) in 1940, earning his BSc in Physics after 2ý years, in 1942. He was conscripted into the navy and, after the war ended, joined the group of Hideki Yukawa at Kyoto University. He was appointed a professor at Kyoto University in 1957.
Yoichiro Nambu was Hayashi's college classmate at UTokyo.
He made additions to the Big Bang nucleosynthesis model that built upon the work of the classic AlpherâÂÂBetheâÂÂGamow paper. Probably his most famous work was the astrophysical calculations that led to the Hayashi tracks of star formation, and the Hayashi limit that puts a limit on star radius. He was also involved in the early study of brown dwarfs, some of the smallest stars formed.
He retired in 1984 and died from pneumonia at a Kyoto hospital on February 28, 2010.