Stanford Earl Woosley (born December 8, 1944) is a physicist, and Professor of Astronomy and Astrophysics. He is the director of the Center for Supernova Research at UCSC. He has published over 300 papers.
Stan Woosley's research centers on theoretical high-energy astrophysics, especially violent explosive events such as supernovae and gamma ray bursts. A focus of interest is in the nucleosynthesis, hydrodynamics, and radiation transport of these events, and in the evolution of massive stars, which sets the stage for such explosions.
Woosley is also co-investigator on the High Energy Transient Explorer-2--a satellite dedicated to the study of gamma-ray bursts, launched by NASA in 2000, and is involved in planning NASA's other missions for gamma-ray astronomy.
His research projects include modeling the evolution of massive stars (8 to 50 times the mass of the sun) through all stages of nuclear burning, in an attempt to obtain realistic pre-supernova stars and a complete depiction of nucleosynthesis for all isotopes lighter than krypton. An example of this sort of work can be found in ApJS, 101, 181, (1995) with application to Galactic chemical evolution discussed in ApJS, 98, 617 (1995).
Woosley's work on the evolution of massive stars, which sets the stage for supernova explosions, helps explain how elements like oxygen and iron are formed, and more massive stars that produce a hypernova. A supernova occurs when the core of a star collapses under the gravitational force of its own mass. The resulting explosion can be as bright as an entire galaxy, releasing immense amounts of energy. The explosion also spews into space all of the chemical elements forged by nuclear fusion reactions during the life of the star and some that are formed during the explosion itself. These materials may then contribute to the formation of new stars and planets. According to Woosley's collapsar model, gamma-ray bursts arise from the collapse of stars that are too massive to successfully explode as supernovae. Instead, they result in what has been termed a hypernova, which produce black holes.