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Icko Iben
Icko Iben, Jr. (June 27, 1931 – June 11, 2025) was an American astronomer and a Distinguished Professor at the University of Illinois at Urbana-Champaign. He received his PhD from the University of Illinois in 1958 with thesis ''Higher order effects in beta decay'', which was jointly supervised by John David Jackson and Joseph Weneser. Iben served on the MIT Physics Department faculty for some time before moving to Illinois, being promoted to associate professor in 1964. He is best known for his contributions to theoretical star models, stellar evolution theory, concerning the production of planetary nebulae, red giant heavy element convection, and modelling of asymptotic branch thermal pulses. Iben was elected to the National Academy of Sciences in 1985. He was awarded the Henry Norris Russell Lectureship in 1989 and the Eddington Medal The Eddington Medal is awarded by the Royal Astronomical Society for investigations of outstanding merit in theoretical astrophysics. It is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Illinois At Urbana-Champaign
The University of Illinois Urbana-Champaign (UIUC, U of I, Illinois, or University of Illinois) is a public land-grant research university in the Champaign–Urbana metropolitan area, Illinois, United States. Established in 1867, it is the founding campus and flagship institution of the University of Illinois System. With over 59,000 students, the University of Illinois is one of the largest public universities by enrollment in the United States. The university contains 16 schools and colleges and offers more than 150 undergraduate and over 100 graduate programs of study. The university holds 651 buildings on and its annual operating budget in 2016 was over $2 billion. The University of Illinois Urbana-Champaign also operates a research park home to innovation centers for over 90 start-up companies and multinational corporations. The University of Illinois Urbana-Champaign is a member of the Association of American Universities and is classified among "R1: Doctoral Univ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John David Jackson (physicist)
John David Jackson (January 19, 1925 – May 20, 2016) was a Canadian–American theoretical physicist. He was a professor at the University of California, Berkeley and a faculty senior scientist emeritus at Lawrence Berkeley National Laboratory. Jackson was a member of the National Academy of Sciences and was well known for his work in nuclear and particle physics, as well as his widely used graduate text on classical electrodynamics. Early life and education Born in London, Ontario, Canada, Jackson attended the University of Western Ontario, receiving a B.Sc. in honors physics and mathematics in 1946. He went on to graduate study at MIT, where he worked under Victor Weisskopf, completing his Ph.D. thesis in 1949. Academic career Jackson held academic appointments successively at McGill University, thanks to Philip Russell Wallace, a prominent Canadian theoretical physicist, (January 1950 – 1957); then the University of Illinois at Urbana–Champaign (1957–1967); and fin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star
A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sky, night; their immense distances from Earth make them appear as fixed stars, fixed points of light. The most prominent stars have been categorised into constellations and asterism (astronomy), asterisms, and many of the brightest stars have proper names. Astronomers have assembled star catalogues that identify the known stars and provide standardized stellar designations. The observable universe contains an estimated to stars. Only about 4,000 of these stars are visible to the naked eye—all within the Milky Way galaxy. A star's life star formation, begins with the gravitational collapse of a gaseous nebula of material largely comprising hydrogen, helium, and traces of heavier elements. Its stellar mass, total mass mainly determines it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Evolution
Stellar evolution is the process by which a star changes over the course of time. Depending on the mass of the star, its lifetime can range from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the current age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are formed from Gravitational collapse, collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main sequence star. Nuclear fusion powers a star for most of its existence. Initially the energy is generated by the fusion of hydrogen atoms at the stellar core, core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planetary Nebula
A planetary nebula is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives. The term "planetary nebula" is a misnomer because they are unrelated to planets. The term originates from the planet-like round shape of these nebulae observed by astronomers through early telescopes. The first usage may have occurred during the 1780s with the English astronomer William Herschel who described these nebulae as resembling planets; however, as early as January 1779, the French astronomer Antoine Darquier de Pellepoix described in his observations of the Ring Nebula, "very dim but perfectly outlined; it is as large as Jupiter and resembles a fading planet". Though the modern interpretation is different, the old term is still used. All planetary nebulae form at the end of the life of a star of intermediate mass, about 1-8 solar masses. It is expected that the Sun will form a planetary nebula at the end of i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Giant
A red giant is a luminous giant star of low or intermediate mass (roughly 0.3–8 solar masses ()) in a late phase of stellar evolution. The stellar atmosphere, outer atmosphere is inflated and tenuous, making the radius large and the surface temperature around or lower. The appearance of the red giant is from yellow-white to reddish-orange, including the stellar classification, spectral types K and M, sometimes G, but also S-type star, class S stars and most carbon stars. Red giants vary in the way by which they generate energy: * most common red giants are stars on the red-giant branch (RGB) that are still stellar nucleosynthesis, fusing hydrogen into helium in a shell surrounding an inert helium core * red-clump stars in the cool half of the horizontal branch, fusing helium into carbon in their cores via the triple-alpha process * asymptotic-giant-branch (AGB) stars with a helium burning shell outside a degenerate carbon–oxygen core, and a hydrogen-burning shell just beyo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asymptotic Giant Branch
The asymptotic giant branch (AGB) is a region of the Hertzsprung–Russell diagram populated by evolved cool luminous stars. This is a period of stellar evolution undertaken by all low- to intermediate-mass stars (about 0.5 to 8 solar masses) late in their lives. Observationally, an asymptotic-giant-branch star will appear as a bright red giant with a luminosity ranging up to thousands of times greater than the Sun. Its interior structure is characterized by a central and largely inert core of carbon and oxygen, a shell where helium is undergoing fusion to form carbon (known as helium burning), another shell where hydrogen is undergoing fusion forming helium (known as hydrogen burning), and a very large envelope of material of composition similar to main-sequence stars (except in the case of carbon stars). Stellar evolution When a star exhausts the supply of hydrogen by nuclear fusion processes in its core, the core contracts and its temperature increases, causing the oute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Academy Of Sciences
The National Academy of Sciences (NAS) is a United States nonprofit, NGO, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the National Academy of Medicine (NAM). As a national academy, new members of the organization are elected annually by current members, based on their distinguished and continuing achievements in original research. Election to the National Academy is one of the highest honors in the scientific field in the United States. Member of the National Academy of Sciences, Members of the National Academy of Sciences serve ''pro bono'' as "advisers to the nation" on science, engineering, and medicine. The group holds a congressional charter under Title 36 of the United States Code. Congress legislated and President Abraham Lincoln signed an Act of Congress (1863) establishing the National Academy of Sciences as an independent, trusted nongovernmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Norris Russell Lectureship
The Henry Norris Russell Lectureship is awarded each year by the American Astronomical Society in recognition of a lifetime of excellence in astronomical research. The idea for the lectureship came from then society President Harlow Shapley in 1945, who led the fund raising drive to collect $10,000 from the membership. One of the major contributors was the Mexican Ambassador to the United States, as Russell had been an important representative at the dedication ceremony for the Tonantzintla Observatory, Mexican National Observatory. The goal was reached in December 1946, using not a little amount of coercive language by Shapley. The first Russell lecturer was, naturally, fellow American astronomer Henry Norris Russell, for whom the award is named. Russell gave a lecture titled "The Royal Road of Eclipses" concerning eclipsing binary stars. Previous lecturers This list of lecturers is from the American Astronomical Society's website. See also * List of astronomy awards Henry Norris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eddington Medal
The Eddington Medal is awarded by the Royal Astronomical Society for investigations of outstanding merit in theoretical astrophysics. It is named after Sir Arthur Eddington. First awarded in 1953, the frequency of the prize has varied over the years, at times being every one, two or three years. Since 2013 it has been awarded annually. Recipients See also * List of astronomy awards * List of physics awards A list is a set of discrete items of information collected and set forth in some format for utility, entertainment, or other purposes. A list may be memorialized in any number of ways, including existing only in the mind of the list-maker, but ... * List of prizes named after people References External links Winners {{Royal Astronomical Society Physics awards Awards established in 1953 Awards of the Royal Astronomical Society 1953 establishments in the United Kingdom Astrophysics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1931 Births
Events January * January 2 – South Dakota native Ernest Lawrence invents the cyclotron, used to accelerate particles to study nuclear physics. * January 4 – German pilot Elly Beinhorn begins her flight to Africa. * January 22 – Sir Isaac Isaacs is sworn in as the first Australian-born Governor-General of Australia. * January 25 – Mohandas Gandhi is again released from imprisonment in India. * January 27 – Pierre Laval forms a government in France. * January 30 – Charlie Chaplin comedy drama film ''City Lights'' receives its public premiere at the Los Angeles Theater with Albert Einstein as guest of honor. Contrary to the current trend in cinema, it is a silent film, but with a score by Chaplin. Critically and commercially successful from the start, it will place consistently in lists of films considered the best of all time. February * February 4 – Soviet leader Joseph Stalin gives a speech calling for rapid industrialization, arguing that only strong indus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
