Astrophysicist in the context of "Nucleosynthetic"

Colin Michael Foale CBE (/foʊl/; born 6 January 1957) is a British-American astrophysicist and a former NASA astronaut. He is a veteran of six space missions, and is the only NASA astronaut to have flown extended missions aboard both Mir and the International Space Station. He was the second Briton in space and the first to perform a space walk. Until 17 April 2008, he held the record for most time spent in space by a US citizen: 374 days, 11 hours, 19 minutes, and as of 2024 he held the cumulative-time-in-space record for a British citizen.

Jayant Vishnu Narlikar FNA, FASc, FTWAS (19 July 1938 – 20 May 2025) was an Indian astrophysicist who performed research on alternative cosmology. He was also an author who wrote textbooks on cosmology, popular science books, and science fiction novels and short stories.

Narlikar studied at Banaras Hindu University and Cambridge University, where he obtained his PhD in 1963 working with Fred Hoyle. After postdoctoral work in Cambridge, in 1972 he was appointed a professor at the Tata Institute of Fundamental Research. In 1988, he became the first director of the Inter-University Centre for Astronomy and Astrophysics (IUCAA).

Nucleosynthesis is the process that creates new atomic nuclei from pre-existing nucleons (protons and neutrons) and nuclei. According to current theories, the first nuclei were formed a few minutes after the Big Bang, through nuclear reactions in a process called Big Bang nucleosynthesis. After about 20 minutes, the universe had expanded and cooled to a point at which these high-energy collisions among nucleons ended, so only the fastest and simplest reactions occurred, leaving our universe containing hydrogen and helium. The rest is traces of other elements such as lithium and the hydrogen isotope deuterium. Nucleosynthesis in stars and their explosions later produced the variety of elements and isotopes that we have today, in a process called cosmic chemical evolution. The amounts of total mass in elements heavier than hydrogen and helium (called 'metals' by astrophysicists) remains small (few percent), so that the universe still has approximately the same composition.

Stars fuse light elements to heavier ones in their cores, giving off energy in the process known as stellar nucleosynthesis. Nuclear fusion reactions create many of the lighter elements, up to and including iron and nickel in the most massive stars. Products of stellar nucleosynthesis remain trapped in stellar cores and remnants except if ejected through stellar winds and explosions. The neutron capture reactions of the r-process and s-process create heavier elements, from iron upwards.

Irwin Ira Shapiro is an American astrophysicist and Timken University Professor at Harvard University. He has been a professor at Harvard since 1982. He was the director of the Center for Astrophysics | Harvard & Smithsonian from 1982 to 2004.

Joseph Hooton Taylor Jr. (born March 29, 1941) is an American astrophysicist and Nobel Prize laureate in Physics for his discovery with Russell Alan Hulse of a "new type of pulsar, a discovery that has opened up new possibilities for the study of gravitation."

Eleanor Margaret Burbidge, FRS (née Peachey; 12 August 1919 – 5 April 2020) was a British-American observational astronomer and astrophysicist. In the 1950s, she was one of the founders of stellar nucleosynthesis and was first author of the influential BFH paper. During the 1960s and 1970s she worked on galaxy rotation curves and quasars, discovering the most distant astronomical object then known. In the 1980s and 1990s she helped develop and utilise the Faint Object Spectrograph on the Hubble Space Telescope. Burbidge was also well known for her work opposing discrimination against women in astronomy while also opposing positive discrimination.

Burbidge held several leadership and administrative posts, including director of the Royal Greenwich Observatory (1973–1975), president of the American Astronomical Society (1976–1978), and president of the American Association for the Advancement of Science (1983). Burbidge worked at the University of London Observatory, Yerkes Observatory of the University of Chicago, the Cavendish Laboratory of the University of Cambridge, the California Institute of Technology, and the University of California San Diego (UCSD). From 1979 to 1988 she was the first director of the Center for Astronomy and Space Sciences at UCSD, where she worked from 1962 until her retirement.

Geoffrey Ronald Burbidge FRS (24 September 1925 – 26 January 2010) was an English astronomy professor and theoretical astrophysicist, most recently at the University of California, San Diego. He was married to astrophysicist Margaret Burbidge and was the second author of the influential BFH paper which she led.

William Alfred Fowler (August 9, 1911 – March 14, 1995) was an American nuclear physicist, later astrophysicist, who, with Subrahmanyan Chandrasekhar, was awarded the 1983 Nobel Prize in Physics. He is known for his theoretical and experimental research into nuclear reactions within stars and the energy elements produced in the process and was one of the authors of the influential BFH paper.

Stace Victor Murray Clube (born 22 October 1934 in London) is an English astrophysicist.

Hélène Courtois, (French pronunciation: [elɛn kuʁtwa]; born 1970) née Di Nella, is a French astrophysicist specialising in cosmography. She is a professor at the University of Lyon 1 and has been a chevalier of the Ordre des Palmes académiques since 2015.

As the director of a research team at the Lyon Institut de Physique des 2 Infinis (IP2I)—formerly the Institute of Nuclear Physics (IPNL)—and co-director of two international teams (Cosmic Flows and CLUES), she is best known for her investigations into the dynamic cosmography of the Universe. Her work has concentrated on the distribution of matter in the large-scale structure of the Universe. In 2006, she participated in the confirmation of the acceleration in the expansion of the Universe via the study of supernovae. In 2014, she proposed a redefinition of the notion of galactic superclusters, and identified the Laniakea Supercluster, an agglomeration that is bigger than the Virgo Supercluster by a factor of 100. In 2017, she showed that cosmic voids produce a repulsive effect resulting in galactic displacements; this may also explain the cold spot in the cosmic microwave background.

Phillip James Edwin Peebles CC OM FRS (born April 25, 1935) is a Canadian-American astrophysicist, astronomer, and theoretical cosmologist who was Albert Einstein Professor in Science, emeritus, at Princeton University. He is widely regarded as one of the world's leading theoretical cosmologists in the period since 1970, with major theoretical contributions to primordial nucleosynthesis, dark matter, the cosmic microwave background, and structure formation.

Peebles was awarded half of the Nobel Prize in Physics in 2019 for his theoretical discoveries in physical cosmology. He shared the prize with Michel Mayor and Didier Queloz for their discovery of an exoplanet orbiting a sun-like star. While much of his work relates to the development of the universe from its first few seconds, he is more skeptical about what we can know about the very beginning, and stated, "It's very unfortunate that one thinks of the beginning whereas in fact, we have no good theory of such a thing as the beginning."

Viktor Amazaspovich Ambartsumian (Russian: Виктор Амазаспович Амбарцумян; Armenian: Վիկտոր Համազասպի Համբարձումյան, Viktor Hamazaspi Hambardzumyan; 18 September [O.S. 5 September] 1908 – 12 August 1996) was a Soviet and Armenian astrophysicist and science administrator. One of the 20th century's leading astronomers, he is widely regarded as the founder of theoretical astrophysics in the Soviet Union.

Educated at Leningrad State University (LSU) and the Pulkovo Observatory, Ambartsumian taught at LSU and founded the Soviet Union's first department of astrophysics there in 1934. He subsequently moved to Soviet Armenia, where he founded the Byurakan Observatory in 1946. It became his institutional base for the decades to come and a major center of astronomical research. He also co-founded the Armenian Academy of Sciences and led it for almost half a century—the entire post-war period. One commentator noted that "science in Armenia was synonymous with the name Ambartsumian." In 1965 Ambartsumian founded the journal Astrofizika and served as its editor for over 20 years.

George Ellery Hale (June 29, 1868 – February 21, 1938) was an American astrophysicist, best known for his discovery of magnetic fields in sunspots, and as the leader or key figure in the planning or construction of several world-leading telescopes; namely, the 40-inch refracting telescope at Yerkes Observatory, 60-inch Hale reflecting telescope at Mount Wilson Observatory, 100-inch Hooker reflecting telescope at Mount Wilson, and the 200-inch Hale reflecting telescope at Palomar Observatory. He played a key role in the foundation of the International Union for Cooperation in Solar Research and the National Research Council, and in developing the California Institute of Technology into a leading research university.

Charles Leonard Bennett (born November 1956) is an American observational astrophysicist. He is a Bloomberg Distinguished Professor, the Alumni Centennial Professor of Physics and Astronomy and a Gilman Scholar at Johns Hopkins University. He is the Principal Investigator of NASA's Wilkinson Microwave Anisotropy Probe (WMAP).

David Saint-Jacques OC OQ FRCGS (Quebec French: [davɪd sẽɪ̯̃nʒã(ŋ)k̚], French pronunciation: [david sɛ̃ʒak]; born 6 January 1970) is a Canadian astronaut with the Canadian Space Agency (CSA). He is also an astrophysicist, engineer, and a physician.

In December 2018, he launched to the International Space Station, as flight engineer on Expeditions 57, 58 and 59; he returned to Earth on 25 June 2019.

Frank Donald Drake (May 28, 1930 – September 2, 2022) was an American astrophysicist and astrobiologist.

He began his career as a radio astronomer, studying the planets of the Solar System and later pulsars. Drake expanded his interests to the search for extraterrestrial intelligence (SETI), beginning with Project Ozma in 1960, an attempt at extraterrestrial communication. He developed the Drake equation, which attempts to quantify the number of intelligent lifeforms that could potentially be discovered. Working with Carl Sagan, Drake helped to design the Pioneer plaque, the first physical message flown beyond the Solar System, and was part of the team that developed the Voyager Golden Record. Drake designed and implemented the Arecibo message in 1974, an extraterrestrial radio transmission of astronomical and biological information about Earth. He is the father of Advanced SETI.

Michel Gustave Édouard Mayor (French pronunciation: [miʃɛl majɔʁ]; born 12 January 1942) is a Swiss astrophysicist and professor emeritus at the University of Geneva's Department of Astronomy. He formally retired in 2007, but remains active as a researcher at the Observatory of Geneva. He is co-laureate of the 2019 Nobel Prize in Physics along with Jim Peebles and Didier Queloz, and the winner of the 2010 Viktor Ambartsumian International Prize and the 2015 Kyoto Prize.

Together with Didier Queloz in 1995, he discovered 51 Pegasi b, the first extrasolar planet orbiting a sun-like star, 51 Pegasi. For this achievement, they were awarded the 2019 Nobel Prize in Physics "for the discovery of an exoplanet orbiting a solar-type star" resulting in "contributions to our understanding of the evolution of the universe and Earth's place in the cosmos".Related to the discovery, Mayor noted that humans will never migrate to such exoplanets since they are "much, much too far away ... [and would take] hundreds of millions of days using the means we have available today". However, due to discoveries by Mayor, searching for extraterrestrial communications from exoplanets may now be a more practical consideration than thought earlier.

Chushiro Hayashi (林 忠四郎, Hayashi Chūshirō; July 25, 1920 – February 28, 2010) was a Japanese astrophysicist. Hayashi tracks on the Hertzsprung–Russell diagram are named after him.