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Solar Corona
In astronomy, a corona (: coronas or coronae) is the outermost layer of a star's Stellar atmosphere, atmosphere. It is a hot but relatively luminosity, dim region of Plasma (physics), plasma populated by intermittent coronal structures such as solar prominence, prominences, coronal loops, and helmet streamers. The Sun's corona lies above the chromosphere and extends millions of kilometres into outer space. Coronal light is typically obscured by diffuse sky radiation and Glare (vision), glare from the solar disk, but can be easily seen by the naked eye during a total solar eclipse or with a specialized coronagraph. Spectroscopic measurements indicate strong ionization in the corona and a plasma temperature in excess of , much hotter than the surface of the Sun, known as the photosphere. is, in turn, derived . History In 1724, French-Italian astronomer Giacomo F. Maraldi recognized that the aura visible during a solar eclipse belongs to the Sun, not to the Moon. In 1809, Span ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Eclipse 1999 4
Solar may refer to: Astronomy * Of or relating to the Sun ** Solar telescope, a special purpose telescope used to observe the Sun ** A device that utilizes solar energy (e.g. "solar panels") ** Solar calendar, a calendar whose dates indicate the position of the Earth on its revolution around the Sun ** Solar eclipse, an eclipse of a sun in which it is obstructed by the moon ** Solar System, the planetary system made up by the Sun and the objects orbiting it * Solar Maximum Mission, a satellite * SOLAR (ISS), an observatory on International Space Station Music * Solar (composition), "Solar" (composition), attributed to Miles Davis * Solar (Red Garland album), ''Solar'' (Red Garland album), 1962 * Solar (Taeyang album), ''Solar'' (Taeyang album), 2010 * ''Solar'', a 2011 album by Rubik (band), Rubik * "Solar", a song by Northlane from ''Mesmer (album), Mesmer'', 2017 * "Solar", a song by Sault from ''Air (Sault album), Air'', 2022 * ”Solar”, a song by Stam1na from ''Taival ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosphere
The photosphere is a star's outer shell from which light is radiated. It extends into a star's surface until the plasma becomes opaque, equivalent to an optical depth of approximately , or equivalently, a depth from which 50% of light will escape without being scattered. A photosphere is the region of a luminous object, usually a star, that is transparent to photons of certain wavelengths. Stars, except neutron stars, have no solid or liquid surface. Therefore, the photosphere is typically used to describe the Sun's or another star's visual surface. Etymology The term ''photosphere'' is derived from Ancient Greek roots, φῶς, φωτός/''phos'', ''photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it being a spherical surface that is perceived to emit light. Temperature The surface of a star is defined to have a temperature given by the effective temperature in the Stefan–Boltzmann law. Various stars have photospheres of vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Flares
A solar flare is a relatively intense, localized emission of electromagnetic radiation in the Stellar atmosphere, Sun's atmosphere. Flares occur in active regions and are often, but not always, accompanied by coronal mass ejections, solar particle events, and other eruptive solar phenomena. The occurrence of solar flares varies with the 11-year solar cycle. Solar flares are thought to occur when stored magnetic energy in the Sun's atmosphere accelerates charged particles in the surrounding Plasma (physics), plasma. This results in the emission of electromagnetic radiation across the electromagnetic spectrum. The typical time profile of these emissions features three identifiable phases: a ''precursor phase'', an ''impulsive phase'' when particle acceleration dominates, and a ''gradual phase'' in which hot plasma injected into the Stellar corona, corona by the flare cools by a combination of radiation and conduction of energy back down to the lower atmosphere. The extreme ultravi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eugene Parker
Eugene Newman Parker (June 10, 1927 – March 15, 2022) was an American solar and plasma physicist. In the 1950s he proposed the existence of the solar wind and that the magnetic field in the outer Solar System would be in the shape of a Parker spiral, predictions that were later confirmed by spacecraft measurements. In 1987, Parker proposed the existence of nanoflares, a leading candidate to explain the coronal heating problem. Parker obtained his PhD from Caltech and spent four years as a postdoctoral researcher at the University of Utah. He joined University of Chicago in 1955 and spent the rest of his career there, holding positions in the physics department, the astronomy and astrophysics department, and the Enrico Fermi Institute. Parker was elected to the National Academy of Sciences in 1967. In 2017, NASA named its Parker Solar Probe in his honor, the first NASA spacecraft named after a living person. Biography Parker was born in Houghton, Michigan to Glenn and H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronagraph
A coronagraph is a telescopic attachment designed to block out the direct light from a star or other bright object so that nearby objects – which otherwise would be hidden in the object's bright glare – can be resolved. Most coronagraphs are intended to view the corona of the Sun, but a new class of conceptually similar instruments (called ''stellar coronagraphs'' to distinguish them from ''solar coronagraphs'') are being used to find extrasolar planets and circumstellar disks around nearby stars as well as host galaxies in quasars and other similar objects with active galactic nuclei (AGN). Invention The coronagraph was introduced in 1931 by the French astronomer Bernard Lyot; since then, coronagraphs have been used at many solar observatories. Coronagraphs operating within Earth's atmosphere suffer from scattered light in the sky itself, due primarily to Rayleigh scattering of sunlight in the upper atmosphere. At view angles close to the Sun, the sky is much bri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bernard Lyot
Bernard Ferdinand Lyot (2 7 February 1897 in Paris – 2 April 1952 in Cairo) was a French astronomer. Biography An avid reader of the works of Camille Flammarion, he became a member of the Société Astronomique de France in 1915 and made his first observations using the society's telescope on rue Serpente in Paris. He soon acquired a telescope and soon upgraded to a . From graduation in 1918 until 1929, he worked as a demonstrator at the École Polytechnique and studied engineering, physics, and chemistry at the University of Paris. From 1920 until his death he worked for the Meudon Observatory, where in 1930 he earned the title of ''Joint Astronomer of the Observatory''. After gaining the title, he earned a reputation of being an expert of polarized and monochromatic light. Throughout the 1930s, he labored to perfect the coronagraph, which he invented to observe the corona without having to wait for a solar eclipse. Most of this work implied painstaking long observation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Cycle
The Solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a periodic 11-year change in the Sun's activity measured in terms of Modern Maximum, variations in the number of observed sunspots on the Sun's surface. Over the period of a solar cycle, levels of solar radiation and ejection of solar material, the number and size of sunspots, solar flares, and coronal loops all exhibit a synchronized fluctuation from a Solar minimum, period of minimum activity to a Solar maximum, period of a maximum activity back to a period of minimum activity. The magnetic field of the Sun flips during each solar cycle, with the flip occurring when the solar cycle is near its maximum. After two solar cycles, the Sun's magnetic field returns to its original state, completing what is known as a Hale cycle. This cycle has been observed for centuries by changes in the Sun's appearance and by terrestrial phenomena such as aurora but was not clearly identified un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre Janssen
Pierre Jules César Janssen (22 February 1824 – 23 December 1907), usually known as Jules Janssen, was a French astronomer who, along with English scientist Joseph Norman Lockyer, is credited with discovering the gaseous nature of the solar chromosphere, but there is no justification for the conclusion that he deserves credit for the co-discovery of the element helium. Life, work, and interests Janssen was born in Paris (During Bourbon Restoration in France) into a cultivated family. His father, César Antoine Janssen (born in Paris, 1780 – 1860) was a well known clarinettist from Dutch/Belgian descent (his father, Christianus Janssen, emigrated from Walloon Brabant to Paris). His mother Pauline Marie Le Moyne (1789 – 1871) was a daughter of the architect Paul Guillaume Le Moyne. Pierre Janssen studied mathematics and physics at the faculty of sciences. He taught at the Lycée Charlemagne in 1853, and in the school of architecture 1865 – 1871, but his energies were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greek Language
Greek (, ; , ) is an Indo-European languages, Indo-European language, constituting an independent Hellenic languages, Hellenic branch within the Indo-European language family. It is native to Greece, Cyprus, Italy (in Calabria and Salento), southern Albania, and other regions of the Balkans, Caucasus, the Black Sea coast, Asia Minor, and the Eastern Mediterranean. It has the list of languages by first written accounts, longest documented history of any Indo-European language, spanning at least 3,400 years of written records. Its writing system is the Greek alphabet, which has been used for approximately 2,800 years; previously, Greek was recorded in writing systems such as Linear B and the Cypriot syllabary. The Greek language holds a very important place in the history of the Western world. Beginning with the epics of Homer, ancient Greek literature includes many works of lasting importance in the European canon. Greek is also the language in which many of the foundational texts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helium
Helium (from ) is a chemical element; it has chemical symbol, symbol He and atomic number 2. It is a colorless, odorless, non-toxic, inert gas, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling point is the lowest among all the Chemical element, elements, and it does not have a melting point at standard pressures. It is the second-lightest and second-most Abundance of the chemical elements, abundant element in the observable universe, after hydrogen. It is present at about 24% of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined. Its abundance is similar to this in both the Sun and Jupiter, because of the very high nuclear binding energy (per nucleon) of helium-4 with respect to the next three elements after helium. This helium-4 binding energy also accounts for why it is a product of both nuclear fusion and radioactive decay. The most common isotope of helium in the universe is helium-4, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norman Lockyer
Sir Joseph Norman Lockyer (17 May 1836 – 16 August 1920) was an English scientist and astronomer. Along with the French scientist Pierre Janssen, he is credited with discovering the gas helium. Lockyer also is remembered for being the founder and first editor of the influential journal ''Nature (journal), Nature''. Biography Lockyer was born in Rugby, Warwickshire. His early introduction to science was through his father, who was a pioneer of the electric telegraph. After a conventional schooling supplemented by travel in Switzerland and France, he worked for some years as a civil servant in the British War Office. He settled in Wimbledon, London, England, Wimbledon, South London after marrying Winifred James, who helped translate at least four French scientific works into English. He was a keen amateur astronomy, amateur astronomer with a particular interest in the Sun. In 1885 he became the world's first professor of astronomical physics at the Royal College of Scienc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
José Joaquín De Ferrer
José Joaquín de Ferrer y Cafranga (Pasaia, October 26, 1763 – Bilbao, May 18, 1818) was a Spanish Basque astronomer. In 1779, aged 17, he was on board the Gipuzcoana Company's '' Nuestra Señora de la Asunción'' off Cape St Vincent when the vessel was captured by the British. After surviving captivity with the help of his family, he undertook studies. In 1801, Ferrer was elected as a member of the American Philosophical Society. The Spanish astronomer was part of the first solar eclipse expeditions. He journeyed to Cuba in 1803 and to New York State New York, also called New York State, is a state in the northeastern United States. Bordered by New England to the east, Canada to the north, and Pennsylvania and New Jersey to the south, its territory extends into both the Atlantic Ocean and ... in 1806 and observed the two solar eclipses successfully. In the description of the solar eclipse in 1806 observed from Kinderhook, New York he coined the word " corona" for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
