|
Sunspot Cycle
The solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a nearly periodic 11-year change in the Sun's activity measured in terms of 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 period of minimum activity to a 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 until 1843. Solar activity, driven by b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunspot Numbers
Sunspots are phenomena on the Sun's photosphere that appear as temporary spots that are darker than the surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic flux that inhibit convection. Sunspots appear within active regions, usually in pairs of opposite magnetic polarity. Their number varies according to the approximately 11-year solar cycle. Individual sunspots or groups of sunspots may last anywhere from a few days to a few months, but eventually decay. Sunspots expand and contract as they move across the surface of the Sun, with diameters ranging from to . Larger sunspots can be visible from Earth without the aid of a telescope. They may travel at relative speeds, or proper motions, of a few hundred meters per second when they first emerge. Indicating intense magnetic activity, sunspots accompany other active region phenomena such as coronal loops, prominences, and reconnection events. Most solar flares and coronal mas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denmark
) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Danish Realm, Kingdom of Denmark , established_title = History of Denmark#Middle ages, Consolidation , established_date = 8th century , established_title2 = Christianization , established_date2 = 965 , established_title3 = , established_date3 = 5 June 1849 , established_title4 = Faroese home rule , established_date4 = 24 March 1948 , established_title5 = European Economic Community, EEC 1973 enlargement of the European Communities, accession , established_date5 = 1 January 1973 , established_title6 = Greenlandic home rule , established_date6 = 1 May 1979 , official_languages = Danish language, Danish , languages_type = Regional languages , languages_sub = yes , languages = German language, GermanGerman is recognised as a protected minority language in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Ellery Hale
George Ellery Hale (June 29, 1868 – February 21, 1938) was an American solar astronomer, best known for his discovery of magnetic fields in sunspots, and as the leader or key figure in the planning or construction of several world-leading telescopes; namely, the 40-inch refracting telescope at Yerkes Observatory, 60-inch Hale reflecting telescope at Mount Wilson Observatory, 100-inch Hooker reflecting telescope at Mount Wilson, and the 200-inch Hale reflecting telescope at Palomar Observatory. He also played a key role in the foundation of the International Union for Cooperation in Solar Research and the National Research Council, and in developing the California Institute of Technology into a leading research university. Early life and education George Ellery Hale was born on June 29, 1868, in Chicago, Illinois, to William Ellery Hale and Mary Browne.Adams 1939, p. 181. He is descended from Thomas Hale of Watton-on-Stone, Hertfordshire, England, whose son emigrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joy's Law (astronomy)
In astronomy, Joy's law describes the distribution of sunspots in active regions and states that the magnitude at which the sunspots are "tilted"—with the leading spot(s) closer to the equator than the trailing spot(s)―grows with the latitude of these regions. Joy's law provides observational support for the operation of the "alpha effect" in solar dynamo action. It is named after Alfred Harrison Joy Alfred Harrison Joy (September 23, 1882 in Greenville, Illinois – April 18, 1973 in Pasadena, California) was an astronomer best known for his work on stellar distances, the radial motion of stars, and variable stars. A crater on the moon has .... References Solar phenomena {{sun-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred Harrison Joy
Alfred Harrison Joy (September 23, 1882 in Greenville, Illinois – April 18, 1973 in Pasadena, California) was an astronomer best known for his work on stellar distances, the radial motion of stars, and variable stars. A crater on the moon has been named in his honor. Early years He was born in Greenville, Illinois, the son of F.P. Joy, a prominent clothing merchant in Greenville and one-time mayor of the town.Allan H. Keith ''Historical Stories: About Greenville and Bond County, IL'' Consulted on August 15, 2007. He received a BA from Greenville College in 1903 and an MA from Oberlin College the next year. Career After graduating, Joy went on to work at the American University of Beirut in the Syrian Protestant College as a professor of astronomy and the director of the observatory. He was forced to return to the U.S. in 1915 because of World War I. In the United States, he worked at the Mount Wilson Observatory from 1915 to 1952. There, he and his colleagues ascertained the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spörer's Law
Spörer's law predicts the variation of sunspot latitudes during a solar cycle. It was discovered by the English astronomer Richard Christopher Carrington around 1861. Carrington's work was refined by the German astronomer Gustav Spörer. At the start of a sunspot cycle, sunspots tend to appear around 30° to 45° latitude on the Sun's surface. As the cycle progresses, sunspots appear at lower and lower latitudes, until they average 15° at solar maximum. The average latitude of sunspots then continues to drift lower, down to about 7° and then while the old sunspot cycle fades, sunspots of the new cycle start appearing at high latitudes. See also * Solar variation * Wolf number * Joy's law (astronomy) In astronomy, Joy's law describes the distribution of sunspots in active region An active region is a temporary region in the Sun's atmosphere characterized by a strong and complex magnetic field. They are often associated with sunspots and are ... References Solar pheno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Christopher Carrington
Richard Christopher Carrington (26 May 1826 – 27 November 1875) was an English amateur astronomer whose 1859 astronomical observations demonstrated the existence of solar flares as well as suggesting their electrical influence upon the Earth and its aurorae; and whose 1863 records of sunspot observations revealed the differential rotation of the Sun. Life Carrington was born at Chelsea, the second son of Richard Carrington, the proprietor of a large brewery at Brentford, and his wife Esther Clarke Aplin. He entered Trinity College, Cambridge, in 1844; but, though destined for the church, rather by his father's than by his own desire, his scientific tendencies gradually prevailed, and received a final impulse towards practical astronomy from Professor Challis's lectures on the subject. This change in the purpose of his life was unopposed, and he had the prospect of ample means; so that it was purely with the object of gaining experience that he applied, shortly after taking ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (journal)
''Science'', also widely referred to as ''Science Magazine'', is the peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature (journal), Nature'' c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Walter Maunder
Edward Walter Maunder (12 April 1851 – 21 March 1928) was an English astronomer. His study of sunspots and the solar magnetic cycle led to his identification of the period from 1645 to 1715 that is now known as the Maunder Minimum. Early and personal life Maunder was born in 1851, in London, the youngest child of a minister of the Wesleyan Society. He attended King's College London but never graduated. He took a job in a London bank to finance his studies. In 1873 Maunder returned to the Royal Observatory, taking a position as a spectroscopic assistant. Shortly after, in 1875, he married Edith Hannah Bustin, who gave birth to six children: four sons (one of whom died in infancy) and two daughters. Following the death of Edith in 1888, in 1890 he met Annie Scott Dill Russell (later Annie Russell Maunder, 1868–1947), a mathematician and astronomer educated at Girton College in Cambridge, with whom he collaborated for the remainder of his life. She worked as a " lady compu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annie S
Annie may refer to: People and fictional characters * Annie (given name), a given name and a list of people and fictional characters with the name * Annie (actress) (born 1975), Indian actress * Annie (singer) (born 1977), Norwegian singer Theatre and film * ''Annie'' (musical), a 1977 musical ** ''Annie'' (1982 film) *** ''Annie'' (1982 film soundtrack) *** '' Annie: A Royal Adventure!'', a 1995 telefilm sequel ** ''Annie'' (1999 film) *** ''Annie'' (1999 film soundtrack) ** ''Annie'' (2014 film) *** ''Annie'' (2014 film soundtrack) * ''Annie'' (1976 film), a British-Italian film Music * ''Annie'' (Anne Murray album) (1972) * "Annie" (song), a 1999 song by Our Lady Peace * "Annie", a song by SafetySuit * "Annie", a song by Pete Townshend from ''Rough Mix'' * "Annie", a 1972 song by Sutherland Brothers * "Annie", a 1995 song by Elastica from the album ''Elastica'' Other uses * Cyclone Annie (other) * ''Annie'' (locomotive) * ''Annie'' (sloop), a ship bui ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gustav Spörer
Friederich Wilhelm Gustav Spörer (23 October 1822 – 7 July 1895) was a German astronomer. He is noted for his studies of sunspots and sunspot cycles. In this regard he is often mentioned together with Edward Maunder. Spörer was the first to note a prolonged period of low sunspot activity from 1645 to 1715. This period is known as the Maunder Minimum. Spörer was a contemporary of Richard Christopher Carrington, an English astronomer. Carrington is generally credited with discovering Spörer's law, which governs the variation of sunspot latitudes during the course of a solar cycle. Spörer added to Carrington's observations of sunspot drift and is sometimes credited with the discovery. The Spörer minimum was a period of low sunspot activity from roughly 1420 to 1570. Life From 1833 to 1840 Spörer attended Friedrich-Wilhelms-Gymnasium in Berlin and afterwards studied mathematics and natural history at Berliner Universität until 1843. He gained his doctorate on 14. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_2007-04-30_T001456.gif "Click for more on -> Sunspot Numbers")
