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Great Refractor
Great refractor refers to a large telescope with a lens, usually the largest refractor at an observatory with an equatorial mount. The preeminence and success of this style in observational astronomy defines an era in modern telescopy in the 19th and early 20th century. Great refractors were large refracting telescopes using achromatic lenses (as opposed to the mirrors of reflecting telescope A reflecting telescope (also called a reflector) is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century by Isaac Newton as an alternati ...s). They were often the largest in the world, or largest in a region. Despite typical designs having smaller apertures than reflectors, great refractors offered a number of advantages and were popular for astronomy. It was also popular to exhibit large refractors at international exhibits, and examples of this include the Trophy Telescope at t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berlin Treptow Archenhold Sternwarte
Berlin ( , ) is the capital and List of cities in Germany by population, largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's List of cities in the European Union by population within city limits, most populous city, according to population within city limits. One of Germany's States of Germany, sixteen constituent states, Berlin is surrounded by the Brandenburg, State of Brandenburg and contiguous with Potsdam, Brandenburg's capital. Berlin's urban area, which has a population of around 4.5 million, is the second most populous urban area in Germany after the Ruhr. The Berlin/Brandenburg Metropolitan Region, Berlin-Brandenburg capital region has around 6.2 million inhabitants and is Metropolitan regions in Germany, Germany's third-largest metropolitan region after the Rhine-Ruhr and Frankfurt Rhine-Main, Rhine-Main regions. Berlin straddles the banks of the Spree (river), Spree, which flows into the Havel (a tributary of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects show a larger parallax than farther objects when observed from different positions, so parallax can be used to determine distances. To measure large distances, such as the distance of a planet or a star from Earth, astronomers use the principle of parallax. Here, the term ''parallax'' is the semi-angle of inclination between two sight-lines to the star, as observed when Earth is on opposite sides of the Sun in its orbit. These distances form the lowest rung of what is called "the cosmic distance ladder", the first in a succession of methods by which astronomers determine the distances to celestial objects, serving as a basis for other distance measurements in astronomy forming the higher rungs of the ladder. Parallax also affects optical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-achromatic Objective
A non-achromatic objective is an objective lens which is not corrected for chromatic aberration. In telescopes they can a be pre-18th century simple single element objective lenses which were used before the invention of doublet achromatic lenses. They can also be specialty monochromatic lenses used in modern research telescopes and other instruments. Non-achromatic telescope objectives Early non-achromatic objectives Early telescope objective, such as those built by Johannes Hevelius and Christiaan Huygens and his brother Constantijn Huygens, Jr., utilized single small (2"-8") positive lenses with enormous focal lengths (up to 150 feet in length in tube telescopes and up to 600 feet in non-tube aerial telescopes). This allowed the observer to use higher magnification while limiting the interfering rainbow halos caused by chromatic aberration (the uncorrected chromatic aberration fell within the large diffraction pattern at focus). Modern non-achromatic objectives Modern instrumen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Percival Lowell Observing Venus From The Lowell Observatory In 1914
Percival (, also spelled Perceval, Parzival), alternatively called Peredur (), was one of King Arthur's legendary Knights of the Round Table. First mentioned by the French author Chrétien de Troyes in the tale ''Perceval, the Story of the Grail'', he is best known for being the original hero in the quest for the Grail, before being replaced in later English and French literature by Galahad. Etymology and origin The earliest reference to Perceval is in Chrétien de Troyes's first Arthurian romance ''Erec et Enide'', where, as "Percevaus li Galois" (Percevaus of Wales), he appears in a list of Arthur's knights; in another of Chrétien's romances, '' Cligés'', he is a "renowned vassal" who is defeated by the knight Cligés in a tournament. He then becomes the protagonist in Chrétien's final romance, ''Perceval, the Story of the Grail''. In the Welsh romance ''Peredur son of Efrawg'', the figure goes by the name Peredur. The name "Peredur" may derive from Welsh ''par'' (spea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hugh Percy, 3rd Duke Of Northumberland
Hugh Percy, 3rd Duke of Northumberland (20 April 178511 February 1847), styled Earl Percy until 1817, was a British aristocrat and Tory politician who served as Lord Lieutenant of Ireland under the Duke of Wellington from 1829 to 1830. Background and education Northumberland was the son of Hugh Percy, 2nd Duke of Northumberland, and Frances Julia, daughter of Peter Burrell. He was educated at Eton and the University of Cambridge ( St John's College). Political career Northumberland entered parliament as the member for Buckingham in July 1806. In September of that year he was elected member for the City of Westminster, on the death of Charles James Fox. He declined to fight the seat at the general election two months later, instead being returned for Launceston. In 1807 he offered himself as a candidate for the county of Northumberland in opposition to Charles, Lord Howick (afterwards the 2nd Earl Grey), who declined to contest the seat. Percy was returned unopposed, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halley's Comet
Halley's Comet or Comet Halley, officially designated 1P/Halley, is a short-period comet visible from Earth every 75–79 years. Halley is the only known short-period comet that is regularly visible to the naked eye from Earth, and thus the only naked-eye comet that can appear twice in a human lifetime. Halley last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061. Halley's periodic returns to the inner Solar System have been observed and recorded by astronomers around the world since at least 240 BC. But it was not until 1705 that the English astronomer Edmond Halley understood that these appearances were reappearances of the same comet. As a result of this discovery, the comet is named after Halley. During its 1986 visit to the inner Solar System, Halley's Comet became the first comet to be observed in detail by spacecraft, providing the first observational data on the structure of a comet nucleus and the mechanism of coma and tail f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Grubb
Thomas Grubb (4 August 1800 – 19 September 1878) was an Irish optician and founder of the Grubb Telescope Company. He was born near Portlaw, County Waterford, Ireland, the son of William Grubb Junior, a prosperous Quaker farmer and his second wife, Eleanor Fayle. Thomas started out in 1830 in Dublin as a metal billiard-table manufacturer. He diversified into making telescopes and erected a public observatory near his factory at 1 Upper Charlemont Street, Portobello, Dublin. As makers of some of the largest and best-known telescopes of the Victorian era, the company was at the forefront of optical and mechanical engineering. His innovations for large telescopes included clock-driven polar mounts, whiffletree mirror mounting cells and Cassegrain reflector optics. Grubb helped build the famous telescope for William Parsons, 3rd Earl of Rosse, at Parsonstown (now known as Birr), County Offaly, Ireland. One of his earliest instruments - the telescope for Markree Observatory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paris
Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. Since the 17th century, Paris has been one of the world's major centres of finance, diplomacy, commerce, fashion, gastronomy, and science. For its leading role in the arts and sciences, as well as its very early system of street lighting, in the 19th century it became known as "the City of Light". Like London, prior to the Second World War, it was also sometimes called the capital of the world. The City of Paris is the centre of the Île-de-France region, or Paris Region, with an estimated population of 12,262,544 in 2019, or about 19% of the population of France, making the region France's primate city. The Paris Region had a GDP of €739 billion ($743 billion) in 2019, which is the highest in Europe. According to the Economist Intelli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Astronomical Society
(Whatever shines should be observed) , predecessor = , successor = , formation = , founder = , extinction = , merger = , merged = , type = NGO, learned society , status = Registered charity , purpose = To promote the sciences of astronomy & geophysics , professional_title = Fellow of the Royal Astronomical Society (FRAS) , headquarters = Burlington House , location = Piccadilly, London , coords = , region_served = , services = , membership = , language = , general = , leader_title = Patron , leader_name = King Charles III , leader_title2 = President , leader_name2 = Mike Edmunds , leader_title3 = Executive Director , leader_name3 = Philip Diamond , leader_title4 = , leader_name4 = , key_peop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monthly Notices Of The Royal Astronomical Society
''Monthly Notices of the Royal Astronomical Society'' (MNRAS) is a peer-reviewed scientific journal covering research in astronomy and astrophysics. It has been in continuous existence since 1827 and publishes letters and papers reporting original research in relevant fields. Despite the name, the journal is no longer monthly, nor does it carry the notices of the Royal Astronomical Society. History The first issue of MNRAS was published on 9 February 1827 as ''Monthly Notices of the Astronomical Society of London'' and it has been in continuous publication ever since. It took its current name from the second volume, after the Astronomical Society of London became the Royal Astronomical Society (RAS). Until 1960 it carried the monthly notices of the RAS, at which time these were transferred to the newly established ''Quarterly Journal of the Royal Astronomical Society'' (1960–1996) and then to its successor journal ''Astronomy & Geophysics'' (since 1997). Until 1965, MNRAS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Joshua Cooper
Edward Joshua Cooper (May 1798 – 23 April 1863) was an Irish landowner, politician and astronomer from Markree Castle in County Sligo. He sat in the House of Commons of the United Kingdom from 1830 to 1841 and from 1857 to 1859, but is best known for his astronomy, and as the creator of Markree Observatory. His observatory was home to the largest refracting (telescope with a lens) of the 1830s (an almost 14 inch astronomical grade Cauchoix of Paris lens, the largest in the World), and the asteroid 9 Metis was discovered there in the 1840s by his assistant. Several astronomical catalogs were also produced in the 19th century there. Early life and family Cooper was the oldest son of Edward Synge Cooper MP (1762–1830), and his wife Anne Verelst, daughter of Bengal Governor Harry Verelst. He was educated at The Royal School in Armagh, at Eton, and then at Christ Church, Oxford. His first marriage was to Sophia L'Estrange, daughter of Colonel Henry Peisley L'Estrange of Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
