(4) Nuclei of galaxies. Almost independent of morphological types, galaxies retain
compact nuclei, roughly of radius 10 pc and mass 10
7 M ☉ . The mass of a nucleus
may have been supplied from the whole region of the galaxy through cloud
collisions. In collision, parts of gas fall into the central region of the galaxy,
where accumulated gases produce massive stars, which evolve fast and give rise
to the explosion of supernovae. Repeated supernova explosions are the origin of
active nuclear phenomena.
Theoretical models of Taketani and Hatanaka’s group belong to the early phase of
galactic astronomy in postwar development.
3.5 Fujita Yoshio and Cool Stars
3.5.1 Life and Works
Fujita is a pioneer in the spectroscopy of cool stars in Japan. During the war he
theoretically derived the dissociation equilibrium of diatomic molecules, and in the
postwar period he promoted spectroscopic observations in the USA and in Japan. He
contributed to the construction of a 188 cm telescope at the OAO and devoted his
later life to the observations of cool stars (Fujita 1986; Osaki 2008; DeVorkin 1997;
Yamashita et al. 2013).
Fujuta Yoshio (藤田良雄, 1908–2012) was born in the city of Fukui in 1908, the
eldest son of Fujita Teizo (藤田貞造), chief editor of the Fukui newspaper. Fukui
Prefecture is in Japan’s snow country in northern part of the country. In the
wintertime, the region is buried in heavy snow, and most of the time it is cloudy
or snowy. In summer, in contrast, the night sky often offers a display of stunning
constellations. According to his reminiscences, his interest in astronomy was
sparked by such beautiful constellations.
In 1928, he entered Tokyo Imperial University and studied theoretical astronomy
under Hagihara and observational astronomy under Hirayama Kiyotsugu. Under
Hirayama’s guidance Fujita conducted spectroscopic observations of the asteroid
Eros with an objective prism and revealed the existence of a thin gaseous envelope
around the solid body of Eros.
After graduating in 1931, he worked at the TAO as a technician. The TAO’s
director was Sotome Kiyofusa, and Fujita was assigned two duties there. One was to
install the newly imported telescope, the Zeiss tower telescope, which consisted of a
heliostat and a grating spectrograph. Upon completion of the telescope at the solar
tower, Fujita began to observe the Sun with this grating spectrograph, but this lasted
for a short period of time only, because he was more drawn toward the second
assignment, laboratory spectroscopy of molecules. He assisted Tanaka Tsutomu (田
中務) in the Department of Physics, Tokyo Imperial University, who visited the
TAO every week to carry out spectroscopic experiments with a vacuum spectrograph for diatomic molecules, particularly for heavy water, D 2 O. Tanaka’s intention
3.5 Fujita Yoshio and Cool Stars
59
compact nuclei, roughly of radius 10 pc and mass 10
7 M ☉ . The mass of a nucleus
may have been supplied from the whole region of the galaxy through cloud
collisions. In collision, parts of gas fall into the central region of the galaxy,
where accumulated gases produce massive stars, which evolve fast and give rise
to the explosion of supernovae. Repeated supernova explosions are the origin of
active nuclear phenomena.
Theoretical models of Taketani and Hatanaka’s group belong to the early phase of
galactic astronomy in postwar development.
3.5 Fujita Yoshio and Cool Stars
3.5.1 Life and Works
Fujita is a pioneer in the spectroscopy of cool stars in Japan. During the war he
theoretically derived the dissociation equilibrium of diatomic molecules, and in the
postwar period he promoted spectroscopic observations in the USA and in Japan. He
contributed to the construction of a 188 cm telescope at the OAO and devoted his
later life to the observations of cool stars (Fujita 1986; Osaki 2008; DeVorkin 1997;
Yamashita et al. 2013).
Fujuta Yoshio (藤田良雄, 1908–2012) was born in the city of Fukui in 1908, the
eldest son of Fujita Teizo (藤田貞造), chief editor of the Fukui newspaper. Fukui
Prefecture is in Japan’s snow country in northern part of the country. In the
wintertime, the region is buried in heavy snow, and most of the time it is cloudy
or snowy. In summer, in contrast, the night sky often offers a display of stunning
constellations. According to his reminiscences, his interest in astronomy was
sparked by such beautiful constellations.
In 1928, he entered Tokyo Imperial University and studied theoretical astronomy
under Hagihara and observational astronomy under Hirayama Kiyotsugu. Under
Hirayama’s guidance Fujita conducted spectroscopic observations of the asteroid
Eros with an objective prism and revealed the existence of a thin gaseous envelope
around the solid body of Eros.
After graduating in 1931, he worked at the TAO as a technician. The TAO’s
director was Sotome Kiyofusa, and Fujita was assigned two duties there. One was to
install the newly imported telescope, the Zeiss tower telescope, which consisted of a
heliostat and a grating spectrograph. Upon completion of the telescope at the solar
tower, Fujita began to observe the Sun with this grating spectrograph, but this lasted
for a short period of time only, because he was more drawn toward the second
assignment, laboratory spectroscopy of molecules. He assisted Tanaka Tsutomu (田
中務) in the Department of Physics, Tokyo Imperial University, who visited the
TAO every week to carry out spectroscopic experiments with a vacuum spectrograph for diatomic molecules, particularly for heavy water, D 2 O. Tanaka’s intention
3.5 Fujita Yoshio and Cool Stars
59