[2] At the Kavli Institute for the Physics and Mathematics of the Universe (IPMU) he was a principal investigator from 2007 to 2017, as well as a project professor from 2008 to 2017, and is since 2017 a visiting senior scientist.
[2] In 2008 he, with his colleagues Keiichi Maeda and Masaomi Tanaka, discovered by using the Subaru Telescope that most core-collapse supernovae are not spherically symmetric but instead elongated in shape.
Their empirical findings indicated that the spectral evolution diversity is not a serious concern in using SNe Ia as cosmological standard candles for determining distances.
[7][8] He was part of the research group that revealed that the exceptionally bright Type Ia supernova named SN 2009dc had a progenitor star with a mass (1.44 M☉) slightly above the Chandrasekhar limit due to its fast rotation.
"[1] In 2019 he received the Hans A. Bethe Prize of the American Physical Society for "lasting contributions to our understanding of the nuclear astrophysics of the universe, including stellar evolution, the synthesis of new elements, the theory of core-collapse and thermonuclear supernovae, and gamma-ray bursts.