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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 University of California, Santa Cruz. 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 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 a star and some that are formed during the explosion itself. These materials may then contribute to the formation of new stars and planets. Woosley's research projects include simulating the evolution of stars 8 to 50 times the mass of the sun, in an attempt to explain how elements like oxygen and iron are formed.
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 a hypernova, which produce black holes.
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.
A supernova is a powerful and luminous explosion of a star. A supernova occurs during the last evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion. The original object, called the progenitor, either collapses to a neutron star or black hole, or is completely destroyed to form a diffuse nebula. The peak optical luminosity of a supernova can be comparable to that of an entire galaxy before fading over several weeks or months.
SN 1987A was a type II supernova in the Large Magellanic Cloud, a dwarf satellite galaxy of the Milky Way. It occurred approximately 51.4 kiloparsecs from Earth and was the closest observed supernova since Kepler's Supernova in 1604. Light and neutrinos from the explosion reached Earth on February 23, 1987 and was designated "SN 1987A" as the first supernova discovered that year. Its brightness peaked in May of that year, with an apparent magnitude of about 3.
In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic events occurring in distant galaxies which represent the brightest and "most powerful class of explosion in the universe." These extreme electromagnetic events are second only to the Big Bang as the most energetic and luminous phenomenon ever known. Gamma-ray bursts can last from ten milliseconds to several hours. After the initial flash of gamma rays, a longer-lived § afterglow is emitted, usually in the longer wavelengths of X-ray, ultraviolet, optical, infrared, microwave or radio frequencies.
High-energy astronomy is the study of astronomical objects that release electromagnetic radiation of highly energetic wavelengths. It includes X-ray astronomy, gamma-ray astronomy, extreme UV astronomy, neutrino astronomy, and studies of cosmic rays. The physical study of these phenomena is referred to as high-energy astrophysics.
A magnetar is a type of neutron star with an extremely powerful magnetic field (~109 to 1011 T, ~1013 to 1015 G). The magnetic-field decay powers the emission of high-energy electromagnetic radiation, particularly X-rays and gamma rays.
A super-luminous supernova is a type of stellar explosion with a luminosity 10 or more times higher than that of standard supernovae. Like supernovae, SLSNe seem to be produced by several mechanisms, which is readily revealed by their light-curves and spectra. There are multiple models for what conditions may produce an SLSN, including core collapse in particularly massive stars, millisecond magnetars, interaction with circumstellar material, or pair-instability supernovae.
The Bruno Rossi Prize is awarded annually by the High Energy Astrophysics division of the American Astronomical Society "for a significant contribution to High Energy Astrophysics, with particular emphasis on recent, original work". Named after astrophysicist Bruno Rossi, the prize is awarded with a certificate and a gift of USD $500, and was first awarded in 1985 to William R. Forman and Christine Jones Forman "for pioneering work in the study of X-ray emission from early type galaxies". It has been awarded 40 times. In 2010, the prize was awarded to William B. Atwood, Peter Michelson and the Fermi Gamma-ray Space Telescope team "for enabling, through the development of the Large Area Telescope, new insights into neutron stars, supernova remnants, cosmic rays, binary systems, active galactic nuclei, and gamma-ray bursts". In 2013, the prize was awarded to Roger W. Romani of Leland Stanford Junior University and Alice Harding of Goddard Space Flight Center for their work in developing the theoretical framework underpinning the many exciting pulsar results from Fermi Gamma-ray Space Telescope.
Nuclear astrophysics studies the origin of the chemical elements and isotopes, and the role of nuclear energy generation, in cosmic sources such as stars, supernovae, novae, and violent binary-star interactions. It is an interdisciplinary part of both nuclear physics and astrophysics, involving close collaboration among researchers in various subfields of each of these fields. This includes, notably, nuclear reactions and their rates as they occur in cosmic environments, and modeling of astrophysical objects where these nuclear reactions may occur, but also considerations of cosmic evolution of isotopic and elemental composition (often called chemical evolution). Constraints from observations involve multiple messengers, all across the electromagnetic spectrum (nuclear gamma-rays, X-rays, optical, and radio/sub-mm astronomy), as well as isotopic measurements of solar-system materials such as meteorites and their stardust inclusions, cosmic rays, material deposits on Earth and Moon). Nuclear physics experiments address stability (i.e., lifetimes and masses) for atomic nuclei well beyond the regime of stable nuclides into the realm of radioactive/unstable nuclei, almost to the limits of bound nuclei (the drip lines), and under high density (up to neutron star matter) and high temperature (plasma temperatures up to 109 K). Theories and simulations are essential parts herein, as cosmic nuclear reaction environments cannot be realized, but at best partially approximated by experiments.
A Type II supernova or SNII results from the rapid collapse and violent explosion of a massive star. A star must have at least eight times, but no more than 40 to 50 times, the mass of the Sun (M☉) to undergo this type of explosion. Type II supernovae are distinguished from other types of supernovae by the presence of hydrogen in their spectra. They are usually observed in the spiral arms of galaxies and in H II regions, but not in elliptical galaxies; those are generally composed of older, low-mass stars, with few of the young, very massive stars necessary to cause a supernova.
Cornelis A. "Neil" Gehrels was an American astrophysicist specializing in the field of gamma-ray astronomy. He was Chief of the Astroparticle Physics Laboratory at NASA's Goddard Space Flight Center (GSFC) from 1995 until his death, and was best known for his work developing the field from early balloon instruments to today's space observatories such as the NASA Swift mission, for which he was the principal investigator. He was leading the WFIRST wide-field infrared telescope forward toward a launch in the mid-2020s. He was a member of the National Academy of Sciences and the American Academy of Arts and Sciences.
Gamma-ray burst progenitors are the types of celestial objects that can emit gamma-ray bursts (GRBs). GRBs show an extraordinary degree of diversity. They can last anywhere from a fraction of a second to many minutes. Bursts could have a single profile or oscillate wildly up and down in intensity, and their spectra are highly variable unlike other objects in space. The near complete lack of observational constraint led to a profusion of theories, including evaporating black holes, magnetic flares on white dwarfs, accretion of matter onto neutron stars, antimatter accretion, supernovae, hypernovae, and rapid extraction of rotational energy from supermassive black holes, among others.
The Hans A. Bethe Prize, is presented annually by the American Physical Society. The prize honors outstanding work in theory, experiment or observation in the areas of astrophysics, nuclear physics, nuclear astrophysics, or closely related fields. The prize consists of $10,000 and a certificate citing the contributions made by the recipient.
Alicia Margarita Soderberg is an American astrophysicist whose research focused on supernovae. She was an assistant professor of astronomy at Harvard University and a postdoctoral fellow at the Harvard-Smithsonian Center for Astrophysics.
Gerald Jay (Jerry) Fishman is an American research astrophysicist, specializing in gamma-ray astronomy. His research interests also include space and nuclear instrumentation and radiation in space. A native of St. Louis, Missouri, Fishman obtained a B.S. with Honors degree in physics from the University of Missouri in 1965, followed by M.S. and Ph.D. degrees in space science from Rice University in 1968 and 1970, respectively.
Fiona A. Harrison is the Kent and Joyce Kresa Leadership Chair of the Division of Physics, Mathematics and Astronomy at Caltech, Harold A. Rosen Professor of Physics at Caltech and the Principal Investigator for NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) mission. She won the Hans A. Bethe Prize in 2020 for her work on NuSTAR.
Chryssa Kouveliotou is a Greek astrophysicist. She is a professor at George Washington University and a retired senior technologist in high-energy astrophysics at NASA's Marshall Space Flight Center in Huntsville, Alabama.
A hypernova is a very energetic supernova which is believed to result from an extreme core collapse scenario. In this case, a massive star collapses to form a rotating black hole emitting twin astrophysical jets and surrounded by an accretion disk. It is a type of stellar explosion that ejects material with an unusually high kinetic energy, an order of magnitude higher than most supernovae, with a luminosity at least 10 times greater. Hypernovae release such intense gamma rays that they often appear similar to a type Ic supernova, but with unusually broad spectral lines indicating an extremely high expansion velocity. Hypernovae are one of the mechanisms for producing long gamma ray bursts (GRBs), which range from 2 seconds to over a minute in duration. They have also been referred to as superluminous supernovae, though that classification also includes other types of extremely luminous stellar explosions that have different origins.
Peter M. Garnavich is a faculty member of the Department of Physics and Astronomy at the University of Notre Dame. His primary research area is the study of supernovae and their diversity. He has also studied gamma ray bursts and cataclysmic variable stars. Garnavich is a member of a supernova search team that contributed to the discovery of dark energy in 1998. At Notre Dame, Garnavich has developed and participated in collaborations using the Spitzer Space Telescope, the Large Binocular Telescope, the Hubble Space Telescope, and the Kepler Space Telescope. He was named a fellow of the American Astronomical Society (AAS) in 2024.
John Craig Wheeler is an American astronomer. He is the Samuel T. and Fern Yanagisawa Regents Professor of Astronomy Emeritus at the University of Texas at Austin. He is known for his theoretical work on supernovae. He is a past president of the American Astronomical Society, a Fellow of that society, and a Fellow of the American Physical Society.
Ken'ichi Nomoto is a Japanese astrophysicist and astronomer, known for his research on stellar evolution, supernovae, and the origin of heavy elements.
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