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Burnham's Nebula
T Tauri is a variable star in the constellation Taurus, the prototype of the T Tauri stars. It was discovered in October 1852 by John Russell Hind. T Tauri appears from Earth amongst the Hyades cluster, not far from ε Tauri, but it is actually 420 light-years behind it and was not formed with the rest of them. The cloud to the west of the system is NGC 1555, known more commonly as Hind's Variable Nebula. Although this system is considered to be the prototype of T Tauri stars, a later phase in a protostar's formation, it is a very atypical T Tauri star. Orbital characteristics and mass The system has three stars: T Tauri North (T Tau N), T Tauri South A (T Tau Sa), and T Tauri South B (T Tau Sb). T Tau N is estimated to be approximately 300 AU away from the southern binary, with the separation of the binary believed to be approximately 7 AU with an orbital period of 27.2±0.7 years. The orbit of T Tau N about the southern binary is poorly constrained, with the perio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Motion Of T Tau S Relative To N
Orbital may refer to: Sciences Chemistry and physics * Atomic orbital * Molecular orbital * Hybrid orbital Astronomy and space flight * Orbit ** Earth orbit Medicine and physiology * Orbit (anatomy), also known as the ''orbital bone'' * Orbitofrontal cortex, a part of the brain used for decision making Business * Orbital Corporation, an Australian engine technology company * Orbital Sciences Corporation, a U.S. satellite launch and defense systems corporation * Orbital ATK, American aerospace manufacturer formed from the merger of Orbital Sciences Corporation and parts of Alliant Techsystems Transportation * Ring road (or ''orbital road'' in some regions) * Orbital (metro), a rapid transit line usually encircling a city centre * Orbital engine Other uses * Orbital (The Culture), artificial worlds from Iain M. Banks's series of science fiction novels, the Culture * Orbital (band), an English electronic dance music duo ** ''Orbital'' (1991 album) ** ''Orbital'' (1993 album) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Lick Telescope
The James Lick Telescope is a refracting telescope built in 1888. It has a lens in diameter—a major achievement in its day. The instrument remains in operation and public viewing is allowed on a limited basis. Also called the "Great Lick Refractor" or simply "Lick Refractor", it was the largest refracting telescope in the world until 1897 and now ranks third, after the 40-inch refractor at the Yerkes Observatory and the Swedish 1-m Solar Telescope. The telescope is located at the University of California's Lick Observatory atop Mount Hamilton at an elevation of above sea level. The instrument is housed inside a dome that is powered by hydraulic systems that raise and lower the floor, rotate the dome and drive the clock mechanism to track the Earth's rotation. The original hydraulic arrangement still operates today, with the exception that the original wind-powered pumps that once filled the reservoirs have been replaced with electric pumps. James Lick is entombed below the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sherburne Wesley Burnham
Sherburne Wesley Burnham (December 12, 1838 – March 11, 1921) was an American astronomer. For more than 50 years Burnham spent all his free time observing the heavens, mainly concerning himself with binary stars. Biography Sherburne Wesley Burnham was born in Thetford, Vermont. His parents were Roswell O. Burnham and Marinda (née Foote) Burnham. He graduated from the academy in Thetford, and that was the extent of his schooling. He taught himself shorthand, and by 1858 was in New York City. Burnham was a reporter for the Union Army in New Orleans during the Civil War. While in New Orleans, he bought a copy of a popular book ''Geography of the Heavens'', which piqued his interest in astronomy. After the war, he moved to Chicago and worked as a court reporter for over 20 years. At night Burnham was an amateur astronomer, except for four years (1888–1892) he worked as a professional astronomer at Lick Observatory. He left court reporting in 1902, but remained ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burnham's Nebula
T Tauri is a variable star in the constellation Taurus, the prototype of the T Tauri stars. It was discovered in October 1852 by John Russell Hind. T Tauri appears from Earth amongst the Hyades cluster, not far from ε Tauri, but it is actually 420 light-years behind it and was not formed with the rest of them. The cloud to the west of the system is NGC 1555, known more commonly as Hind's Variable Nebula. Although this system is considered to be the prototype of T Tauri stars, a later phase in a protostar's formation, it is a very atypical T Tauri star. Orbital characteristics and mass The system has three stars: T Tauri North (T Tau N), T Tauri South A (T Tau Sa), and T Tauri South B (T Tau Sb). T Tau N is estimated to be approximately 300 AU away from the southern binary, with the separation of the binary believed to be approximately 7 AU with an orbital period of 27.2±0.7 years. The orbit of T Tau N about the southern binary is poorly constrained, with the perio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HH255
HH may refer to: Organizations * Happy Hippie Foundation, a non-profit organization founded by Miley Cyrus * Hartmann House Preparatory School, an independent preparatory school in Harare, Zimbabwe * Heirs Holdings, a Nigerian conglomerate with diversified interests * Helly Hansen, a Norwegian brand specializing in clothing and gear for oceans and mountains * Heywood Hill, a bookshop in London Science and technology * Hh, a signalling molecule in Drosophila named for the Hedgehog signaling pathway * hh blood group, a rare blood type * Henderson–Hasselbalch equation, in biology and chemistry * Herbig–Haro object, in astronomy * Hitchhiker Program, a NASA program established in 1984 * Hodgkin–Huxley model, an electrical model of neurons * Microsoft Compiled HTML Help (hh.exe) * Hereditary haemochromatosis Transportation * HH (Court Street Shuttle) a defunct line on the New York City Subway from 1936 to 1946 * HH (Rockaway Shuttle), from 1962 to 1972 * HH Ferry route between ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T Tauri Outflow
T, or t, is the twentieth letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''tee'' (pronounced ), plural ''tees''. It is derived from the Semitic Taw 𐤕 of the Phoenician and Paleo-Hebrew script (Aramaic and Hebrew Taw ת/𐡕/, Syriac Taw ܬ, and Arabic ت Tāʼ) via the Greek letter τ (tau). In English, it is most commonly used to represent the voiceless alveolar plosive, a sound it also denotes in the International Phonetic Alphabet. It is the most commonly used consonant and the second most commonly used letter in English-language texts. History ''Taw'' was the last letter of the Western Semitic and Hebrew alphabets. The sound value of Semitic ''Taw'', Greek alphabet Tαυ (''Tau''), Old Italic and Latin T has remained fairly constant, representing in each of these; and it has also kept its original basic shape in most of these alphabets. Use in wr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Field
A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to the magnetic field. A permanent magnet's magnetic field pulls on ferromagnetic materials such as iron, and attracts or repels other magnets. In addition, a nonuniform magnetic field exerts minuscule forces on "nonmagnetic" materials by three other magnetic effects: paramagnetism, diamagnetism, and antiferromagnetism, although these forces are usually so small they can only be detected by laboratory equipment. Magnetic fields surround magnetized materials, and are created by electric currents such as those used in electromagnets, and by electric fields varying in time. Since both strength and direction of a magnetic field may vary with location, it is described mathematically by a function assigning a vector to each point of space, cal ... [...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] |
Quasar
A quasar is an extremely Luminosity, luminous active galactic nucleus (AGN). It is pronounced , and sometimes known as a quasi-stellar object, abbreviated QSO. This emission from a galaxy nucleus is powered by a supermassive black hole with a mass ranging from millions to tens of billions of solar masses, surrounded by a gaseous accretion disc. Gas in the disc falling towards the black hole heats up because of friction and releases energy in the form of electromagnetic radiation. The radiant energy of quasars is enormous; the most powerful quasars have luminosity, luminosities thousands of times greater than that of a galaxy such as the Milky Way. Usually, quasars are categorized as a subclass of the more general category of AGN. The redshifts of quasars are of Expansion of the universe, cosmological origin. The term originated as a Contraction (grammar), contraction of "quasi-stellar ''[star-like]'' radio source"—because quasars were first identified during the 1950s as sour ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Fusion
Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles ( neutrons or protons). The difference in mass between the reactants and products is manifested as either the release or absorption of energy. This difference in mass arises due to the difference in nuclear binding energy between the atomic nuclei before and after the reaction. Nuclear fusion is the process that powers active or main-sequence stars and other high-magnitude stars, where large amounts of energy are released. A nuclear fusion process that produces atomic nuclei lighter than iron-56 or nickel-62 will generally release energy. These elements have a relatively small mass and a relatively large binding energy per nucleon. Fusion of nuclei lighter than these releases energy (an exothermic process), while the fusion of heavier nuclei results in energy retained by the product nucleons, and the resulting reaction is endo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
