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Donald Osterbrock
Donald Edward Osterbrock (July 13, 1924 – January 11, 2007) was an American astronomer, best known for his work on star formation and on the history of astronomy. Biography Osterbrock was born in Cincinnati. His father was an electrical engineer. He served with the US Army in the Second World War, making weather observations in the Pacific. He did undergraduate classes in physics at the University of Chicago as part of his weather training. He was educated at the University of Chicago, where he received bachelor's and master's degrees in physics and a PhD in astronomy in 1952. He was a student of Subrahmanyan Chandrasekhar while working at University of Chicago's Yerkes Observatory. His work there with William Wilson Morgan and Stewart Sharpless showed the existence of the Milky Way's spiral arms. He became a post-doctoral researcher, instructor and assistant professor at the California Institute of Technology until 1958. He was then appointed assistant professor at the Uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cincinnati
Cincinnati ( ) is a city in the U.S. state of Ohio and the county seat of Hamilton County. Settled in 1788, the city is located at the northern side of the confluence of the Licking and Ohio rivers, the latter of which marks the state line with Kentucky. The city is the economic and cultural hub of the Cincinnati metropolitan area. With an estimated population of 2,256,884, it is Ohio's largest metropolitan area and the nation's 30th-largest, and with a city population of 309,317, Cincinnati is the third-largest city in Ohio and 64th in the United States. Throughout much of the 19th century, it was among the top 10 U.S. cities by population, surpassed only by New Orleans and the older, established settlements of the United States eastern seaboard, as well as being the sixth-most populous city from 1840 until 1860. As a rivertown crossroads at the junction of the North, South, East, and West, Cincinnati developed with fewer immigrants and less influence from Europe than Ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postdoctoral Researcher
A postdoctoral fellow, postdoctoral researcher, or simply postdoc, is a person professionally conducting research after the completion of their doctoral studies (typically a PhD). The ultimate goal of a postdoctoral research position is to pursue additional research, training, or teaching in order to have better skills to pursue a career in academia, research, or any other field. Postdocs often, but not always, have a temporary academic appointment, sometimes in preparation for an academic faculty position. They continue their studies or carry out research and further increase expertise in a specialist subject, including integrating a team and acquiring novel skills and research methods. Postdoctoral research is often considered essential while advancing the scholarly mission of the host institution; it is expected to produce relevant publications in peer-reviewed academic journals or conferences. In some countries, postdoctoral research may lead to further formal qualificati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy
A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. Galaxies, averaging an estimated 100 million stars, range in size from dwarfs with less than a hundred million stars, to the largest galaxies known – supergiants with one hundred trillion stars, each orbiting its galaxy's center of mass. Most of the mass in a typical galaxy is in the form of dark matter, with only a few percent of that mass visible in the form of stars and nebulae. Supermassive black holes are a common feature at the centres of galaxies. Galaxies are categorized according to their visual morphology as elliptical, spiral, or irregular. Many are thought to have supermassive black holes at their centers. The Milky Way's central black hole, known as Sagittarius A*, has a mass four million times greater than the Sun. As o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma (physics)
Plasma () 1, where \nu_ is the electron gyrofrequency and \nu_ is the electron collision rate. It is often the case that the electrons are magnetized while the ions are not. Magnetized plasmas are ''anisotropic'', meaning that their properties in the direction parallel to the magnetic field are different from those perpendicular to it. While electric fields in plasmas are usually small due to the plasma high conductivity, the electric field associated with a plasma moving with velocity \mathbf in the magnetic field \mathbf is given by the usual Lorentz force, Lorentz formula \mathbf = -\mathbf\times\mathbf, and is not affected by Debye shielding. Mathematical descriptions To completely describe the state of a plasma, all of the particle locations and velocities that describe the electromagnetic field in the plasma region would need to be written down. However, it is generally not practical or necessary to keep track of all the particles in a plasma. Therefore, plasma physicist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Kentucky
The University of Kentucky (UK, UKY, or U of K) is a Public University, public Land-grant University, land-grant research university in Lexington, Kentucky. Founded in 1865 by John Bryan Bowman as the Agricultural and Mechanical College of Kentucky, the university is one of the state's two land-grant universities (the other being Kentucky State University) and the institution with the highest enrollment in the state, with 30,545 students as of fall 2019. The institution comprises 16 colleges, a graduate school, 93 undergraduate programs, 99 master's degrees, master programs, 66 Doctor of Philosophy, doctoral programs, and four professional programs. It is Carnegie Classification of Institutions of Higher Education, classified among "R1: Doctoral Universities – Very high research activity". According to the National Science Foundation, Kentucky spent $393 million on research and development in 2018, ranking it 63rd in the nation. The University of Kentucky has fifteen libraries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gary Ferland
Gary Joseph Ferland (born May 10, 1951, in Washington D.C.) is an American astrophysicist. He is a professor of Physics and Astronomy at The University of Kentucky. He joined the University of TexasAstronomy Departmentin 1973 where he received hiPh.D.in 1978, studying the 1975 explosion of V1500 Cygni at McDonald Observatory. From 1978 to 1980 he was at the Institute of Astronomy, Cambridge where he worked with Martin Rees on International Ultraviolet Explorer observations of radio galaxies He joined the faculty of the University of Kentucky in 1980. The American Astronomical Society's Astronomy Genealogy Project lists the 17 PhDs he has supervised. Ferland is a Fellow of the American Astronomical Society, and has served on their Governing Council in addition to their Publications Board. He was named Fellow of the American Association for the Advancement of Science in 2023 and is a Fellow of the Royal Astronomical Society. He is a long-time member of the Internationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Galactic Nucleus
An active galactic nucleus (AGN) is a compact region at the center of a galaxy that has a much-higher-than-normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars. Such excess non-stellar emission has been observed in the radio, microwave, infrared, optical, ultra-violet, X-ray and gamma ray wavebands. A galaxy hosting an AGN is called an "active galaxy". The non-stellar radiation from an AGN is theorized to result from the accretion of matter by a supermassive black hole at the center of its host galaxy. Active galactic nuclei are the most luminous persistent sources of electromagnetic radiation in the universe, and as such can be used as a means of discovering distant objects; their evolution as a function of cosmic time also puts constraints on models of the cosmos. The observed characteristics of an AGN depend on several properties such as the mass of the central black hole, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diffuse Nebula
A nebula ('cloud' or 'fog' in Latin; pl. nebulae, nebulæ or nebulas) is a distinct luminescent part of interstellar medium, which can consist of ionized, neutral or molecular hydrogen and also cosmic dust. Nebulae are often star-forming regions, such as in the "Pillars of Creation" in the Eagle Nebula. In these regions, the formations of gas, dust, and other materials "clump" together to form denser regions, which attract further matter, and eventually will become dense enough to form stars. The remaining material is then thought to form planets and other planetary system objects. Most nebulae are of vast size; some are hundreds of light-years in diameter. A nebula that is visible to the human eye from Earth would appear larger, but no brighter, from close by. The Orion Nebula, the brightest nebula in the sky and occupying an area twice the angular diameter of the full Moon, can be viewed with the naked eye but was missed by early astronomers. Although denser than the space sur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emeritus
''Emeritus'' (; female: ''emerita'') is an adjective used to designate a retired chair, professor, pastor, bishop, pope, director, president, prime minister, rabbi, emperor, or other person who has been "permitted to retain as an honorary title the rank of the last office held". In some cases, the term is conferred automatically upon all persons who retire at a given rank, but in others, it remains a mark of distinguished service awarded selectively on retirement. It is also used when a person of distinction in a profession retires or hands over the position, enabling their former rank to be retained in their title, e.g., "professor emeritus". The term ''emeritus'' does not necessarily signify that a person has relinquished all the duties of their former position, and they may continue to exercise some of them. In the description of deceased professors emeritus listed at U.S. universities, the title ''emeritus'' is replaced by indicating the years of their appointmentsThe Protoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lick Observatory
The Lick Observatory is an astronomical observatory owned and operated by the University of California. It is on the summit of Mount Hamilton, in the Diablo Range just east of San Jose, California, United States. The observatory is managed by the University of California Observatories, with headquarters on the University of California, Santa Cruz campus, where its scientific staff moved in the mid-1960s. It is named after James Lick. The first new moon of Jupiter to be identified since the time of Galileo was discovered at this observatory; Amalthea, the planet's fifth moon, was discovered at this observatory in 1892. Early history Lick Observatory is the world's first permanently occupied mountain-top observatory. The observatory, in a Classical Revival style structure, was constructed between 1876 and 1887, from a bequest from James Lick of $700,000, . Lick, originally a carpenter and piano maker, had arrived from Peru in San Francisco, California, in late 1847; after ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrophysics
Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline said, Astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space–''what'' they are, rather than ''where'' they are." Among the subjects studied are the Sun, other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background. Emissions from these objects are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. Because astrophysics is a very broad subject, ''astrophysicists'' apply concepts and methods from many disciplines of physics, including classical mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomy
Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest include planets, natural satellite, moons, stars, nebulae, galaxy, galaxies, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond atmosphere of Earth, Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Babylonian astronomy, Babylonians, Greek astronomy, Greeks, Indian astronomy, Indians, Egyptian astronomy, Egyptians, Chinese astronomy, Chinese, Maya civilization, Maya, and many anc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
