Ken'ichi Nomoto

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Ken'ichi Nomoto is a Japanese astrophysicist and astronomer.

Nomoto received his PhD in astronomy from the University of Tokyo in 1974 and was then a research fellow of the Japan Society for the Promotion of Science . In 1976 he became an Assistant Professor at Ibaraki University and in 1982 Assistant Professor at the University of Tokyo, where he was Associate Professor in 1985 and Professor in 1993. He is at the Kavli Institute for Mathematics and Physics of the Universe (IPMU) in Tokyo as a project professor and lead scientist.

Nomoto deals with supernova explosions and the enrichment of the universe with heavy chemical elements.

In 2008, with Keiichi Maeda and Masaomi Tanaka at the Subaru telescope , he found out that most core collapse supernovae are not spherically symmetrical, but rather elongated in shape. Together with Maeda and others, he was able to explain deviations in the appearance of type Ia supernovae from the asymmetrical structure of supernova explosions, which had previously fueled doubts about their use as standard candles for determining distances. Also in 2008 he and colleagues were able to study light echoes of the supernova SN 1572 by Tycho Brahe (1572), that is, light from the supernova explosion that was reflected in the surroundings and only reached Earth in the present. The observation confirmed that it was a Type Ia supernova. In 2009, together with colleagues, he discovered a particularly bright Type Ia supernova whose predecessor star, due to its rapid rotation, had a mass slightly above the Chandrasekhar limit of 1.44 solar masses. The discovery has implications for the common use of Type Ia supernovae as standard candles for measuring distances in the universe. In 2010, he and his colleagues succeeded in detecting a supernova (SN 2005cz), which, with ten solar masses of the predecessor star, is on the limit for supernovae to occur at all. In 2012, he explained the fact that often no companion star was found in Type Ia supernovae by the fact that the companion star of the binary system developed into a helium-rich white dwarf before the supernova explosion, which is difficult to observe. This was previously a problem for SD scenarios of the formation of Type 1 supernovae, in which a white dwarf subtracts mass from its companion star (such as a red giant) and then explodes in a supernova.

In 1989 he received the Nishina Memorial Prize , in 1995 the Japan Academy Medal and in 2010 the medal of the Institute for Astrophysics in Paris. In 2015 he received the Marcel Grossmann Award for pioneering work on the role of binary star systems in the development of massive stars . He showed that binary star systems open different pathways in the evolution of massive stars, with different types of supernovae, hypernovae, gamma-ray flashes and neutron stars and black holes as end stations. He made theoretical investigations as well as those in observational astronomy. For 2019 he was awarded the Hans A. Bethe Prize of the American Physical Society .

Fonts (selection)

  • with C. Kobayashi, N. Tominaga: Nucleosynthesis in Stars and the Chemical Enrichment of Galaxies , Annual Review of Astronomy and Astrophysics, Volume 51, 2013, pp. 457-509
  • with N. Iwamoto, H. Umeda, N. Tominaga, K. Maeda: The First Chemical Enrichment in the Universe and the Formation of Hyper Metal-Poor Stars , Science, Volume 309, 2005, pp. 451-453
  • with PA Mazzali, KS Kawabata, K. Maeda u. a .: An Asymmetric Energetic Type Ic Supernova Viewed Off-Axis, and a Link to Gamma Ray Bursts , Science, Volume 308, 2005, pp. 1284-1287

Web links

Individual evidence

  1. ↑ Supernovae are NOT round: Spectroscopy by the Subaru Telescope , University of Tokyo, January 31, 2008
  2. ↑ Strengthening the case for the dark energy! Type Ia supernova are after all uniform , IPMU 2010. Reference to: Maeda, Nomoto u. a., An asymmetric explosion as the origin of spectral evolution diversity in type Ia supernovae, Nature, July 1, 2010
  3. ↑ Subaru sees Tycho's New Star via Echo Light: K.Nomoto and His International Team , IPMU, December 1, 2008, reference to Nomoto and others. a., ycho Brahe's 1572 supernova as a standard type Ia as revealed by its light-echo spectrum, Nature, Volume 456, 2008, pp. 617-619
  4. ^ The Most Luminous Type Ia Supernova , IPMU, 2009
  5. ↑ A Massive Star Origin for An Unusual Helium-Rich Supernovae in An Elliptical Galaxy , IPMU, referring to Kawabata, Maeda, Nomoto, Tanaka, Nature, May 20, 2010
  6. ↑ Hachizu, Kato, Nomoto, Final Fates of Rotating White Dwarfs and Their Companions in the Single Degenerate Model of Type Ia Supernovae, Astroph. J. Letters, Volume 756, 2012, No. 1, L4, IPMU
  7. ↑ In the competing DD scenario, on the other hand, two white dwarfs with a high carbon-oxygen content fuse.
  8. ↑ Asian Scientist, 2015
personal data
SURNAME Nomoto, Ken'ichi
BRIEF DESCRIPTION Japanese astrophysicist
DATE OF BIRTH 20th century