Professor Hideyo Kawakita

Area and Subject Taught Astronomy
Research Theme(s) Chemical evolution of the Galaxy, origin of the solar system
Academic Degrees Doctor of Science
Keywords for Research Field Astronomy, Planetary Science, Solar System, Comets
Office Phone Number 81-75-705-1612
e-mail Not Public

Research Overview

It is thought that our solar system formed from a molecular cloud of gas and dust grains 4.6 billion years ago. Many extra-solar planetary systems have been discovered, and the number of planets in the universe is much greater than previously expected. However, the birth and evolution of these planetary systems are still not adequately understood. What sort of planetary systems are created under what conditions? Even basic points like these are still unclear.
My main research interest is the formation of our solar system. The solar system is the closest object to us, and can be observed in the most detail. However, 4.6 billion years have passed since the formation of our solar system. How can we investigate the environment at the time of the solar system's formation? Small objects called "primordial objects," which have undergone almost no change in 4.6 billion years, are crucial for this purpose. My research focuses particularly on comets comprised of ice and dust grains.
Comets hold the information about the formation of the solar system, and by investigating their composition and other characteristics, we can obtain formation conditions such as the temperature of the molecular cloud from which the solar system was born. I also interested in novae that provided materials used for the solar system formation. Isotopic ratios of carbon and nitrogen formed in novae are quite different from those formed in evolved stars and in super-novae. Some of the pre-solar grains found in meteorites could be related to those origins.

Notable Publications and Works in the Last Three Years

  1. Kawakita et al., “Mid-infrared Spectroscopic Observations of the Dust-forming Classical Nova V2676 Oph”, Astronomical Journal, 153, id. 74, 2017.
  2. Kawakita et al., “The evolution of photospheric temperature in nova V2676 Oph toward the formation of C2 and CN during its near-maximum phase”, Pub. Astron. Soc. Japan, 68, id. 87, 2016.
  3. Kawakita et al., “Formation of C2 and CN in nova V2676Oph around its visual brightness maximum”, Pub. Astron. Soc. Japan, 62, id. 17, 2015.
  4. Shinnaka, Kawakita, Kobayashi, Nagashima, Boice, “14NH2/15NH2 Ratio in Comet C/2012 S1 (ISON) Observed during its Outburst in 2013 November”, Astrophysical Journal, 782, L16-L19, 2014.
  5. Nagashima, Arai, Kajikawa, Kawakita, Kitao, Arasaki, Taguchi, Ikeda, “The Transient Molecular Envelope in the Outflow of the Nova V2676 Oph during its Early Phase”, Astrophysical Journal, 780, L26-L29, 2014.
  6. Shinnaka, Kawakita, Kobayashi, Naka, Arai, Arasaki, Kitao, Taguchi, Ikeda, “Optical low-dispersion spectroscopic observations of Comet 103P/Hartley 2 at Koyama Astronomical Observatory during the EPOXI flyby”, Icarus, 222, 734-737, 2013.
  7. Kawakita et al., "Parent volatiles in Comet 103P/Hartley 2 observed by Keck II with NIRSPEC during the 2010 apparition", Icarus, 222, pp.723-733, 2013.