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Messier 67
Messier 67 (also known as M67 or NGC 2682) and sometimes called the King Cobra cluster or the Golden Eye cluster is an open cluster in the southern, equatorial half of Cancer. It was discovered by Johann Gottfried Koehler in 1779. Estimates of its age range between 3.2 and 5 billion years. Distance estimates are likewise varied, but typically are . Estimates of 855, 840, and 815 pc were established via binary star modelling and infrared color-magnitude diagram fitting. Description M67 is not the oldest known open cluster, but there are few Milky Way clusters known to be older, and none of those is closer than M67. It is a paradigm study object in stellar evolution: * it is well-populated * has negligible amounts of dust obscuration * all its stars are at the same distance and age, save for approximately 30 anomalous blue stragglers M67 is one of the most-studied open clusters, yet estimates of its physical parameters such as age, mass, and number of stars of a given type, va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M67 Mazur , an open star cluster in the constellation Cancer
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M67, M-67, or M.67 may refer to: * M-67 (Michigan highway), a state highway in Michigan in the United States * M67 grenade, a fragmentation hand grenade * M67 motorway, a motorway in Greater Manchester, England * M67 recoilless rifle, an anti-tank weapon * The M-67 submachine gun; see MEMS M-52/60 * M67 Zippo, a flamethrower tank variant of the M48 Patton tank * BMW M67, a 1998 turbodiesel automobile engine * Mauser M67, a rifle made by Kongsberg Våpenfabrikk based on M/98k actions, which again were based on captured Karabiner 98k (K98k) actions * Macchi M.67, an Italian racing floatplane of 1929 * Messier 67 Messier 67 (also known as M67 or NGC 2682) and sometimes called the King Cobra cluster or the Golden Eye cluster is an open cluster in the southern, equatorial half of Cancer. It was discovered by Johann Gottfried Koehler in 1779. Estimates of it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Dwarf
A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes from the emission of residual thermal energy; no fusion takes place in a white dwarf. The nearest known white dwarf is at 8.6 light years, the smaller component of the Sirius binary star. There are currently thought to be eight white dwarfs among the hundred star systems nearest the Sun. The unusual faintness of white dwarfs was first recognized in 1910. The name ''white dwarf'' was coined by Willem Luyten in 1922. White dwarfs are thought to be the final evolutionary state of stars whose mass is not high enough to become a neutron star or black hole. This includes over 97% of the other stars in the Milky Way. After the hydrogen- fusing period of a main-sequence star of low or medium mass ends, such a star will expand to a red giant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principle
A principle is a proposition or value that is a guide for behavior or evaluation. In law, it is a Legal rule, rule that has to be or usually is to be followed. It can be desirably followed, or it can be an inevitable consequence of something, such as the laws observed in nature or the way that a system is constructed. The principles of such a system are understood by its users as the essential characteristics of the system, or reflecting system's designed purpose, and the effective operation or use of which would be impossible if any one of the principles was to be ignored. A system may be explicitly based on and implemented from a document of principles as was done in IBM's IBM System/360 architecture, 360/370 ''Principles of Operation''. Examples of principles are, entropy (other), entropy in a number of fields, least action in physics, those in descriptive comprehensive and fundamental law: doctrines or assumptions forming normative rules of conduct, separation of chur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler (spacecraft)
The Kepler space telescope is a disused space telescope launched by NASA in 2009 to discover Earth-sized planets orbiting other stars. Named after astronomer Johannes Kepler, the spacecraft was launched into an Earth-trailing heliocentric orbit. The principal investigator was William J. Borucki. After nine and a half years of operation, the telescope's reaction control system fuel was depleted, and NASA announced its retirement on October 30, 2018. Designed to survey a portion of Earth's region of the Milky Way to discover Earth-size exoplanets in or near habitable zones and estimate how many of the billions of stars in the Milky Way have such planets, Kepler's sole scientific instrument is a photometer that continually monitored the brightness of approximately 150,000 main sequence stars in a fixed field of view. These data were transmitted to Earth, then analyzed to detect periodic dimming caused by exoplanets that cross in front of their host star. Only planets whose orbi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johns Hopkins University
Johns Hopkins University (Johns Hopkins, Hopkins, or JHU) is a private university, private research university in Baltimore, Maryland. Founded in 1876, Johns Hopkins is the oldest research university in the United States and in the western hemisphere. It consistently ranks among the most prestigious universities in the United States and the world. The university was named for its first benefactor, the American entrepreneur and Quaker philanthropist Johns Hopkins. Hopkins' $7 million bequest to establish the university was the largest Philanthropy, philanthropic gift in U.S. history up to that time. Daniel Coit Gilman, who was inaugurated as :Presidents of Johns Hopkins University, Johns Hopkins's first president on February 22, 1876, led the university to revolutionize higher education in the U.S. by integrating teaching and research. In 1900, Johns Hopkins became a founding member of the American Association of Universities. The university has led all Higher education in the U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leibniz Institute For Astrophysics Potsdam
Leibniz Institute for Astrophysics Potsdam (AIP) is a German research institute. It is the successor of the Berlin Observatory founded in 1700 and of the Astrophysical Observatory Potsdam (AOP) founded in 1874. The latter was the world's first observatory to emphasize explicitly the research area of astrophysics. The AIP was founded in 1992, in a re-structuring following the German reunification. The AIP is privately funded and member of the Leibniz Association. It is located in Babelsberg in the state of Brandenburg, just west of Berlin, though the Einstein Tower solar observatory and the great refractor telescopeGreat Refractor telescope at Telegrafenberg on Telegrafenberg i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomy And Astrophysics
''Astronomy & Astrophysics'' is a monthly peer-reviewed scientific journal covering theoretical, observational, and instrumental astronomy and astrophysics. The journal is run by a Board of Directors representing 27 sponsoring countries plus a representative of the European Southern Observatory. The journal is published by EDP Sciences and the editor-in-chief is . History Origins ''Astronomy and Astrophysics'' (A&A) was created as an answer to the publishing scenario found in Europe in the 1960s. At that time, multiple journals were being published in several countries around the continent. These journals usually had a limited number of subscribers, and published articles in languages other than English, resulting in a small number of citations compared to American and British journals. Starting in 1963, conversations between astronomers from European countries assessed the need for a common astronomical journal. On 8 April 1968, leading astronomers from Belgium, Denmark, Fran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Segregation
In astronomy, dynamical mass segregation is the process by which heavier members of a gravitationally bound system, such as a star cluster, tend to move toward the center, while lighter members tend to move farther away from the center. Equipartition of kinetic energy During a close encounter of two members of the cluster, the members exchange both energy and momentum. Although energy can be exchanged in either direction, there is a statistical tendency for the kinetic energy of the two members to equalize during an encounter; this statistical phenomenon is called equipartition, and is similar to the fact that the expected kinetic energy of the molecules of a gas are all the same at a given temperature. Since kinetic energy is proportional to mass times the square of the speed, equipartition requires the less massive members of a cluster to be moving faster. The more massive members will thus tend to sink into lower orbits (that is, orbits closer to the center of the cluste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Classification
In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grating into a spectrum exhibiting the Continuum (spectrum), rainbow of colors interspersed with spectral lines. Each line indicates a particular chemical element or molecule, with the line strength indicating the abundance of that element. The strengths of the different spectral lines vary mainly due to the temperature of the photosphere, although in some cases there are true abundance differences. The ''spectral class'' of a star is a short code primarily summarizing the ionization state, giving an objective measure of the photosphere's temperature. Most stars are currently classified under the Morgan–Keenan (MK) system using the letters ''O'', ''B'', ''A'', ''F'', ''G'', ''K'', and ''M'', a sequence from the hottest (''O'' type) to the coo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Main Sequence
In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell. Stars on this band are known as main-sequence stars or dwarf stars. These are the most numerous true stars in the universe and include the Sun. After condensation and ignition of a star, it generates thermal energy in its dense core region through nuclear fusion of hydrogen into helium. During this stage of the star's lifetime, it is located on the main sequence at a position determined primarily by its mass but also based on its chemical composition and age. The cores of main-sequence stars are in hydrostatic equilibrium, where outward thermal pressure from the hot core is balanced by the inward pressure of gravitational collapse from the overlying layers. The strong dependence of the rate of energy ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomy & Astrophysics Supplement Series
''Astronomy & Astrophysics'' is a monthly peer-reviewed scientific journal covering theoretical, observational, and instrumental astronomy and astrophysics. The journal is run by a Board of Directors representing 27 sponsoring countries plus a representative of the European Southern Observatory. The journal is published by EDP Sciences and the editor-in-chief is . History Origins ''Astronomy and Astrophysics'' (A&A) was created as an answer to the publishing scenario found in Europe in the 1960s. At that time, multiple journals were being published in several countries around the continent. These journals usually had a limited number of subscribers, and published articles in languages other than English, resulting in a small number of citations compared to American and British journals. Starting in 1963, conversations between astronomers from European countries assessed the need for a common astronomical journal. On 8 April 1968, leading astronomers from Belgium, Denmark, Franc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
