The CNO cycle is one of the two known sets of fusion reactions by which stars convert hydrogen to helium, the other being the proton–proton chain reaction, which is more efficient at the Sun's core temperature. The CNO cycle is hypothesized to be dominant in stars that are more than 1.3 times as massive as the Sun.
The proton–proton chain, also commonly referred to as the p–p chain, is one of two known sets of nuclear fusion reactions by which stars convert hydrogen to helium. It dominates in stars with masses less than or equal to that of the Sun, whereas the CNO cycle, the other known reaction, is suggested by theoretical models to dominate in stars with masses greater than about 1.3 solar masses.
Hans Albrecht Bethe was a German-American physicist who made major contributions to nuclear physics, astrophysics, quantum electrodynamics and solid-state physics, and received the Nobel Prize in Physics in 1967 for his work on the theory of stellar nucleosynthesis. For most of his career, Bethe was a professor at Cornell University.
Stanford Earl Woosley 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.
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.
Gerald Edward Brown was an American theoretical physicist who worked on nuclear physics and astrophysics. Since 1968 he had been a professor at the Stony Brook University. He was a distinguished professor emeritus of the C. N. Yang Institute for Theoretical Physics at Stony Brook University.
Friedrich-Karl "Friedel“ Thielemann is a German-Swiss theoretical astrophysicist.
William David Arnett is a Regents Professor of Astrophysics at Steward Observatory, University of Arizona, known for his research on supernova explosions, the formation of neutron stars or black holes by gravitational collapse, and the synthesis of elements in stars; he is author of the monograph Supernovae and Nucleosynthesis which deals with these topics. Arnett pioneered the application of supercomputers to astrophysical problems, including neutrino radiation hydrodynamics, nuclear reaction networks, instabilities and explosions, supernova light curves, and turbulent convective flow in two and three dimensions.
James Michael Lattimer is a nuclear astrophysicist who works on the dense nuclear matter equation of state and neutron stars. He is currently a distinguished professor at Stony Brook University.
Vassiliki Kalogera is a Greek astrophysicist. She is a professor at Northwestern University and the director of the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). She is a leading member of the LIGO Collaboration that observed gravitational waves in 2015.
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.
Stuart Louis Shapiro is an American theoretical astrophysicist, who works on numerical relativity with applications in astrophysics, specialising in compact objects such as neutron stars and black holes.
The Herman Feshbach Prize in Theoretical Nuclear Physics is a prize awarded annually by the American Physical Society to recognize and encourage outstanding achievements in theoretical nuclear physics. The $10,000 prize is in honor of Herman Feshbach of MIT. The prize, inaugurated in 2014, is awarded to one person or is shared among two to three persons when all of the recipients are credited with the same accomplishment.
Supernova neutrinos are weakly interactive elementary particles produced during a core-collapse supernova explosion. A massive star collapses at the end of its life, emitting on the order of 1058 neutrinos and antineutrinos in all lepton flavors. The luminosity of different neutrino and antineutrino species are roughly the same. They carry away about 99% of the gravitational energy of the dying star as a burst lasting tens of seconds. The typical supernova neutrino energies are 10 to 20 MeV. Supernovae are considered the strongest and most frequent source of cosmic neutrinos in the MeV energy range.
James Wellington Truran Jr. was an American physicist, known for his research in nuclear astrophysics.
Ken'ichi Nomoto is a Japanese astrophysicist and astronomer, known for his research on stellar evolution, supernovae, and the origin of heavy elements.
Madappa Prakash is an Indian-American nuclear physicist and astrophysicist, known for his research on the physics of neutron stars and heavy-ion collisions.
George Michael Fuller is an American theoretical physicist, known for his research on nuclear astrophysics involving weak interactions, neutrino flavor-mixing, and quark matter, as well as the hypothetical nuclear matter.
Almudena Arcones Segovia is a Spanish-German nuclear astrophysicist whose research topics have included the creation and decay of heavy elements through the r-process, and neutrino-driven outflows, in energetic stellar events including supernovae and neutron star mergers. She is a professor of theoretical astrophysics at Technische Universität Darmstadt in Germany, and a researcher in the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt.
