7.2 Structure and Evolution of Stars
Theoretical studies of stellar structure, formation, and evolution were initiated by
Hayashi Chushiro (林忠四郎, 1920–2010) and advanced by his school in Kyoto
University and the University of Tokyo.
7.2.1 Life and Works of Hayashi Chushiro
Hayashi was born in Kyoto the fourth son of Seijiro Hayashi, a manager at a small
finance company. In 1940, Chushiro enrolled in the Department of Physics, Tokyo
Imperial University, where he was exposed to astrophysics through a paper by
G. Gamow and M. Schenberg on the Urca process (1941). Urca was the name of a
casino in Rio de Janeiro, called Cassino da Urca, where Gamow and Schenberg first
discussed the physical process containing neutrinos. According to the story,
Schenberg told Gamow that the energy in the nucleus of a supernova disappeared
as quickly as money disappeared at a roulette table (Nadyozhin 1995). The Urca
process opened Hayashi’s eyes to astrophysics, to which he devoted his life’s work.
In 1942, upon graduation, he was conscripted into the navy. After the war ended
in 1945, he returned to his hometown of Kyoto and joined the group of Yukawa
Hideki at Kyoto University, where he immersed himself in the study of nuclear
physics and astrophysics (Fig. 7.1).
In 1957, he was appointed professor of physics at Kyoto University and remained
there until his retirement in 1984. His research activity lasted over 60 years, from the
1940s to before his death in 2010. His main works were on the following subjects,
which overlapped during his active years:
1. Nuclear physics: 1947–1960
2. Chemical evolution in the early Universe: 1950–1963
3. Stellar evolution, Hayashi track: 1959–1980
4. Formation of planetary system: 1975–1990
In the following section, the main works of Hayashi and his school are presented.
For his achievements in astrophysics, Hayashi received many prizes, including
the Order of Culture (1986) (文化勲章) from the Japanese government, the
Table 7.1 Membership of
Astronomical Society of Japan
in Postwar Period
Year
Special members
Normal members
Total
1950
126
694
820
1960
222
787
1009
1970
360
1427
1787
1980
510
1481
1991
1990
795
1545
2340
2000
1370
1400
2770
After Astronomical Herald, Astronomical Society of Japan
176
7 Postwar Development of Astrophysics, 1946–2000 (Part II: Astrophysics)
Theoretical studies of stellar structure, formation, and evolution were initiated by
Hayashi Chushiro (林忠四郎, 1920–2010) and advanced by his school in Kyoto
University and the University of Tokyo.
7.2.1 Life and Works of Hayashi Chushiro
Hayashi was born in Kyoto the fourth son of Seijiro Hayashi, a manager at a small
finance company. In 1940, Chushiro enrolled in the Department of Physics, Tokyo
Imperial University, where he was exposed to astrophysics through a paper by
G. Gamow and M. Schenberg on the Urca process (1941). Urca was the name of a
casino in Rio de Janeiro, called Cassino da Urca, where Gamow and Schenberg first
discussed the physical process containing neutrinos. According to the story,
Schenberg told Gamow that the energy in the nucleus of a supernova disappeared
as quickly as money disappeared at a roulette table (Nadyozhin 1995). The Urca
process opened Hayashi’s eyes to astrophysics, to which he devoted his life’s work.
In 1942, upon graduation, he was conscripted into the navy. After the war ended
in 1945, he returned to his hometown of Kyoto and joined the group of Yukawa
Hideki at Kyoto University, where he immersed himself in the study of nuclear
physics and astrophysics (Fig. 7.1).
In 1957, he was appointed professor of physics at Kyoto University and remained
there until his retirement in 1984. His research activity lasted over 60 years, from the
1940s to before his death in 2010. His main works were on the following subjects,
which overlapped during his active years:
1. Nuclear physics: 1947–1960
2. Chemical evolution in the early Universe: 1950–1963
3. Stellar evolution, Hayashi track: 1959–1980
4. Formation of planetary system: 1975–1990
In the following section, the main works of Hayashi and his school are presented.
For his achievements in astrophysics, Hayashi received many prizes, including
the Order of Culture (1986) (文化勲章) from the Japanese government, the
Table 7.1 Membership of
Astronomical Society of Japan
in Postwar Period
Year
Special members
Normal members
Total
1950
126
694
820
1960
222
787
1009
1970
360
1427
1787
1980
510
1481
1991
1990
795
1545
2340
2000
1370
1400
2770
After Astronomical Herald, Astronomical Society of Japan
176
7 Postwar Development of Astrophysics, 1946–2000 (Part II: Astrophysics)