|
Bonnard J. Teegarden
Bonnard John Teegarden (born August 23, 1940) is an American astrophysicist formerly with NASA's Goddard Space Flight Center, now retired. He spent most of his career studying cosmic gamma rays and is best known to the public for leading the team that discovered Teegarden's star in 2003. Education Teegarden grew up in Fair Haven, New Jersey and graduated from Rumson-Fair Haven Regional High School in Rumson in 1958. He earned a Bachelor of Science from the Massachusetts Institute of Technology in 1962 and a Doctor of Philosophy from the University of Maryland in 1967. His thesis was "A Study of Low Energy Galactic Cosmic Rays" and his advisor was Frank B. McDonald. Career The discovery of Teegarden's star The discovery of Teegarden's star came as somewhat of a surprise as no close-by stars had been discovered for many decades. Teegarden's team found this star in data taken years earlier by an unrelated program searching for near-Earth asteroids. The real excitement was from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Americans
Americans are the citizens and nationals of the United States of America.; ; Although direct citizens and nationals make up the majority of Americans, many dual citizens, expatriates, and permanent residents could also legally claim American nationality. The United States is home to people of many racial and ethnic origins; consequently, American culture and law do not equate nationality with race or ethnicity, but with citizenship and an oath of permanent allegiance. Overview The majority of Americans or their ancestors immigrated to the United States or are descended from people who were brought as slaves within the past five centuries, with the exception of the Native American population and people from Hawaii, Puerto Rico, Guam, and the Philippine Islands, who became American through expansion of the country in the 19th century, additionally America expanded into American Samoa, the U.S. Virgin Islands and Northern Mariana Islands in the 20th century. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light-year
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 (one million million, or billion in long scale). As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in a vacuum in one Julian year (365.25 days). Because it includes the time-measurement word "year", the term ''light-year'' is sometimes misinterpreted as a unit of time. The ''light-year'' is most often used when expressing distances to stars and other distances on a galactic scale, especially in non-specialist contexts and popular science publications. The unit most commonly used in professional astronomy is the parsec (symbol: pc, about 3.26 light-years) which derives from astrometry; it is the distance at which one astronomical unit subtends an angle of one second of arc. D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
21st-century American Physicists
The 1st century was the century spanning AD 1 (Roman numerals, I) through AD 100 (Roman numerals, C) according to the Julian calendar. It is often written as the or to distinguish it from the 1st century BC (or BCE) which preceded it. The 1st century is considered part of the Classical era, epoch, or History by period, historical period. The 1st century also saw the Christianity in the 1st century, appearance of Christianity. During this period, Europe, North Africa and the Near East fell under increasing domination by the Roman Empire, which continued expanding, most notably conquering Britain under the emperor Claudius (AD 43). The reforms introduced by Augustus during his long reign stabilized the empire after the turmoil of the previous century's civil wars. Later in the century the Julio-Claudian dynasty, which had been founded by Augustus, came to an end with the suicide of Nero in AD 68. There followed the famous Year of Four Emperors, a brief period of civil war and inst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Place Of Birth Missing (living People)
Place may refer to: Geography * Place (United States Census Bureau), defined as any concentration of population ** Census-designated place, a populated area lacking its own municipal government * "Place", a type of street or road name ** Often implies a dead end (street) or cul-de-sac * Place, based on the Cornish word "plas" meaning mansion * Place, a populated place, an area of human settlement ** Incorporated place (see municipal corporation), a populated area with its own municipal government * Location (geography), an area with definite or indefinite boundaries or a portion of space which has a name in an area Placenames * Placé, a commune in Pays de la Loire, Paris, France * Plače, a small settlement in Slovenia * Place (Mysia), a town of ancient Mysia, Anatolia, now in Turkey * Place, New Hampshire, a location in the United States * Place House, a 16th-century mansion largely remodelled in the 19th century, in Fowey, Cornwall * Place House, a 19th-century mans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stars Named After People
Over the past few centuries, a small number of stars have been named after individual people. It is common in astronomy for objects to be given names, in accordance with accepted astronomical naming conventions. Most stars have not been given proper names, relying instead on alphanumeric designations in star catalogues. However, a few hundred had either long-standing traditional names (usually from the Arabic) or historic names from frequent usage. In addition, many stars have catalogue designations that contain the name of their compiler or discoverer. This includes Wolf, Ross, Bradley, Piazzi, Lacaille, Struve, Groombridge, Lalande, Krueger, Mayer, Weisse, Gould, Luyten and others. For example, Wolf 359 was discovered and catalogued by Max Wolf. Various private organizations claim to name stars in honor of people in exchange for a fee, but these names are used only within their own publications, and are not recognized by the scientific community. Names approved by the IAU Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annapolis, Maryland
Annapolis ( ) is the capital city of the U.S. state of Maryland and the county seat of, and only incorporated city in, Anne Arundel County. Situated on the Chesapeake Bay at the mouth of the Severn River, south of Baltimore and about east of Washington, D.C., Annapolis forms part of the Baltimore–Washington metropolitan area. The 2020 census recorded its population as 40,812, an increase of 6.3% since 2010. This city served as the seat of the Confederation Congress, formerly the Second Continental Congress, and temporary national capital of the United States in 1783–1784. At that time, General George Washington came before the body convened in the new Maryland State House and resigned his commission as commander of the Continental Army. A month later, the Congress ratified the Treaty of Paris of 1783, ending the American Revolutionary War, with Great Britain recognizing the independence of the United States. The city and state capitol was also the site of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrophysics Data System
The SAO/NASA Astrophysics Data System (ADS) is an online database of over 16 million astronomy and physics papers from both peer reviewed and non-peer reviewed sources. Abstracts are available free online for almost all articles, and full scanned articles are available in Graphics Interchange Format (GIF) and Portable Document Format (PDF) for older articles. It was developed by the National Aeronautics and Space Administration (NASA), and is managed by the Smithsonian Astrophysical Observatory. ADS is a powerful research tool and has had a significant impact on the efficiency of astronomical research since it was launched in 1992. Literature searches that previously would have taken days or weeks can now be carried out in seconds via the ADS search engine, which is custom-built for astronomical needs. Studies have found that the benefit to astronomy of the ADS is equivalent to several hundred million US dollars annually, and the system is estimated to have tripled the reader ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleosynthesis
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 fus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compton Gamma Ray Observatory
The Compton Gamma Ray Observatory (CGRO) was a space observatory detecting photons with energies from 20 k eV to 30 GeV, in Earth orbit from 1991 to 2000. The observatory featured four main telescopes in one spacecraft, covering X-rays and gamma rays, including various specialized sub-instruments and detectors. Following 14 years of effort, the observatory was launched from Space Shuttle ''Atlantis'' during STS-37 on April 5, 1991, and operated until its deorbit on June 4, 2000. It was deployed in low Earth orbit at to avoid the Van Allen radiation belt. It was the heaviest astrophysical payload ever flown at that time at . Costing $617 million, the CGRO was part of NASA's " Great Observatories" series, along with the Hubble Space Telescope, the Chandra X-ray Observatory, and the Spitzer Space Telescope. It was the second of the series to be launched into space, following the Hubble Space Telescope. The CGRO was named after Arthur Compton, an American ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
INTEGRAL
In mathematics, an integral assigns numbers to functions in a way that describes displacement, area, volume, and other concepts that arise by combining infinitesimal data. The process of finding integrals is called integration. Along with differentiation, integration is a fundamental, essential operation of calculus,Integral calculus is a very well established mathematical discipline for which there are many sources. See and , for example. and serves as a tool to solve problems in mathematics and physics involving the area of an arbitrary shape, the length of a curve, and the volume of a solid, among others. The integrals enumerated here are those termed definite integrals, which can be interpreted as the signed area of the region in the plane that is bounded by the graph of a given function between two points in the real line. Conventionally, areas above the horizontal axis of the plane are positive while areas below are negative. Integrals also refer to the concept of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pioneer 10
''Pioneer 10'' (originally designated Pioneer F) is an American space probe, launched in 1972 and weighing , that completed the first mission to the planet Jupiter. Thereafter, ''Pioneer 10'' became the first of five artificial objects to achieve the escape velocity needed to leave the Solar System. This space exploration project was conducted by the NASA Ames Research Center in California. The space probe was manufactured by TRW Inc. ''Pioneer 10'' was assembled around a hexagonal bus with a diameter parabolic dish high-gain antenna, and the spacecraft was spin stabilized around the axis of the antenna. Its electric power was supplied by four radioisotope thermoelectric generators that provided a combined 155 watts at launch. It was launched on March 3, 1972, at 01:49:00 UTC (March 2 local time), by an Atlas-Centaur expendable vehicle from Cape Canaveral, Florida. Between July 15, 1972, and February 15, 1973, it became the first spacecraft to traverse the asteroi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmic Ray
Cosmic rays are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own galaxy, and from distant galaxies. Upon impact with Earth's atmosphere, cosmic rays produce showers of secondary particles, some of which reach the surface, although the bulk is deflected off into space by the magnetosphere or the heliosphere. Cosmic rays were discovered by Victor Hess in 1912 in balloon experiments, for which he was awarded the 1936 Nobel Prize in Physics. Direct measurement of cosmic rays, especially at lower energies, has been possible since the launch of the first satellites in the late 1950s. Particle detectors similar to those used in nuclear and high-energy physics are used on satellites and space probes for research into cosmic rays. Data from the Fermi Space Telescope (2013) have been interpreted as evi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
