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The Most Famous

ASTRONOMERS from Japan

This page contains a list of the greatest Japanese Astronomers. The pantheon dataset contains 531 Astronomers, 20 of which were born in Japan. This makes Japan the birth place of the 7th most number of Astronomers behind Italy and Netherlands.

Top 10

The following people are considered by Pantheon to be the top 10 most legendary Japanese Astronomers of all time. This list of famous Japanese Astronomers is sorted by HPI (Historical Popularity Index), a metric that aggregates information on a biography’s online popularity. Visit the rankings page to view the entire list of Japanese Astronomers.

1. Kiyotsugu Hirayama (1874 - 1943)

With an HPI of 47.31, Kiyotsugu Hirayama is the most famous Japanese Astronomer. His biography has been translated into 18 different languages on wikipedia.

Kiyotsugu Hirayama (平山清次, Hirayama Kiyotsugu, October 3, 1874 – April 8, 1943) was a Japanese astronomer, best known for his discovery that many asteroid orbits were more similar to one another than chance would allow, leading to the concept of asteroid families, now called "Hirayama families" in his honour.

2. Tsutomu Seki (1930 - )

With an HPI of 47.14, Tsutomu Seki is the 2nd most famous Japanese Astronomer. His biography has been translated into 24 different languages.

Tsutomu Seki (関勉, Seki Tsutomu, born November 3, 1930) is a Japanese amateur astronomer and discoverer of minor planets and comets, born in Kōchi, Japan.

3. Chushiro Hayashi (1920 - 2010)

With an HPI of 45.81, Chushiro Hayashi is the 3rd most famous Japanese Astronomer. His biography has been translated into 18 different languages.

Chushiro Hayashi (林忠四郎, Hayashi Chūshirō, July 25, 1920 – February 28, 2010) was a Japanese astrophysicist. Hayashi tracks on the Hertzsprung–Russell diagram are named after him. Hayashi was born in Kyoto and enrolled at the Imperial University of Tokyo in 1940, earning his BSc in Physics after 2½ 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. He made additions to the Big Bang nucleosynthesis model that built upon the work of the classic Alpher–Bethe–Gamow 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.

4. Takeshi Urata (1947 - 2012)

With an HPI of 45.13, Takeshi Urata is the 4th most famous Japanese Astronomer. His biography has been translated into 26 different languages.

Takeshi Urata (浦田武, Urata Takeshi, 1947 – December 15, 2012) was a Japanese astronomer. He was a prolific discoverer of asteroids, observing at Nihondaira Observatory. In 1978 he became the first amateur to discover a minor planet (2090 Mizuho) in over fifty years, which he named after his daughter, Mizuho. His pioneering feat led to an upsurge in such discoveries. In the ten years that followed, amateurs from Japan discovered 160 minor planets. Urata shared his observation data with peer astronomers in Japan on a periodical called "Tenkai" (the Heavens), as well as contributed to academic journals such as Advances in Space Research and participated in poster presentations at astronomical conferences. Urata co-discovered the periodic comet 112P/Urata-Niijima in 1986. One of the most active amateur astronomers in Japan, he was also an editor of the Japanese Ephemerides of Minor Planets. The 1927-discovered asteroid 3722 Urata is named after him.

5. Yuji Hyakutake (1950 - 2002)

With an HPI of 43.67, Yuji Hyakutake is the 5th most famous Japanese Astronomer. His biography has been translated into 17 different languages.

Yuji Hyakutake (百武裕司, Hyakutake Yūji, July 7, 1950, Shimabara, Nagasaki – April 10, 2002, Kokubu, Kagoshima) was a Japanese amateur astronomer who discovered Comet C/1996 B2, also known as Comet Hyakutake on January 31, 1996, while using 25×150 binoculars. Hyakutake graduated from the Kyushu Sangyo University as a photography major and started working at a newspaper in Fukuoka. He first became interested in astronomy after seeing Comet Ikeya–Seki in 1965. He began searching for comets in 1989. In 1993, he moved to Hayato for because “the skies were much clearer there” and so he could better continue his search for comets. His first discovery was Comet C/1995 Y1, on December 26, 1995. Hyakutake discovered C/1996 B2 while looking for C/1995 Y1, a comet he had discovered a few weeks before. He died in Kokubu, Kagoshima, in 2002 at age 51 of an aneurysm which had led to internal bleeding. Asteroid 7291 Hyakutake is named after him.

6. Hisashi Kimura (1870 - 1943)

With an HPI of 42.64, Hisashi Kimura is the 6th most famous Japanese Astronomer. His biography has been translated into 16 different languages.

Hisashi Kimura (木村栄, Kimura Hisashi, October 4, 1870 – September 26, 1943) was a Japanese astronomer originally from Kanazawa, Ishikawa. He devoted his career to the study and measurement of variation in latitude, building upon the work of Seth Carlo Chandler, who discovered the Chandler wobble. In 1899, he became the first director of the International Latitude Observatory at Mizusawa, Japan. He won the Gold Medal of the Royal Astronomical Society in 1936. He was one of the first people to be awarded the Order of Culture when it was established in 1937. The crater Kimura on the Moon is named after him, the same for the asteroid 6233 Kimura.

7. Hiroki Kosai (1933 - )

With an HPI of 42.31, Hiroki Kosai is the 7th most famous Japanese Astronomer. His biography has been translated into 18 different languages.

Hiroki Kosai (香西洋樹, Kōsai Hiroki, born 8 February 1933) is a Japanese astronomer with the Kiso Observatory. He is best known for helping to popularize astronomy in Japan and for his observations of comets and asteroids, most notably with his co-discovery the comet 1976 XVI. He is credited by the Minor Planet Center (MPC) with the discovery of nearly 100 asteroids.

8. Seiji Ueda (1952 - )

With an HPI of 42.15, Seiji Ueda is the 8th most famous Japanese Astronomer. His biography has been translated into 19 different languages.

Seiji Ueda (上田清二, Ueda Seiji, born 1952) is a Japanese astronomer. He is a prolific discoverer of minor planets. Between 1987 and 2000, Ueda (in collaboration with Hiroshi Kaneda) discovered 705 asteroids. He holds an MD and Ph.D. from Stanford University and is on the staff at the Graduate University for Advanced Study in Japan. The inner main-belt asteroid 4676 Uedaseiji, discovered in 1990, is named for him.

9. Kiichirō Furukawa (1929 - 2016)

With an HPI of 42.14, Kiichirō Furukawa is the 9th most famous Japanese Astronomer. His biography has been translated into 16 different languages.

Kiichirō Furukawa (Japanese: 古川麒一郎, Hepburn: Furukawa Kiichirō, Kunrei: Hurukawa Kiitirô, 22 July 1929 – 29 June 2016) was a Japanese astronomer and discoverer of minor planets at the Tokyo Astronomical Observatory. Furukawa was also associated with Nagoya University Department of Astrophysics.

10. Okuro Oikawa (1896 - 1970)

With an HPI of 41.99, Okuro Oikawa is the 10th most famous Japanese Astronomer. His biography has been translated into 16 different languages.

Okuro Oikawa (及川奥郎, Oikawa Okurō, 1896–1970) was a Japanese astronomer and discoverer of minor planets. He is credited by the Minor Planet Center with the discovered 8 asteroids between 1927 and 1929. The outer main-belt asteroid 2667 Oikawa was named in his memory. Naming citation was published on 1 June 1996 (M.P.C. 27329).

People

Pantheon has 20 people classified as astronomers born between 1870 and 1961. Of these 20, 13 (65.00%) of them are still alive today. The most famous living astronomers include Tsutomu Seki, Hiroki Kosai, and Seiji Ueda. The most famous deceased astronomers include Kiyotsugu Hirayama, Chushiro Hayashi, and Takeshi Urata.