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Jan Woltjer (astronomer)
Jan Woltjer (3 August 1891, Amsterdam – 28 January 1946, Leiden) was a Dutch astronomer. Woltjer was the son of the classical scholar Jan Woltjer. On 13 December 1916 he married Hillegonda de Vries in Groningen. He worked and taught at Leiden University, where Gerard P. Kuiper was one of his students. He was the father of the astronomer Lodewijk Woltjer (1930–2019), who was the director general of the European Southern Observatory from 1975 to 1987. The crater Woltjer on the Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ... and the asteroid 1795 Woltjer are both named after him. References External links Website Leiden professors 1891 births 1946 deaths 20th-century Dutch astronomers Academic staff of Leiden University Scientists from Amsterdam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amsterdam
Amsterdam ( , , , lit. ''The Dam on the River Amstel'') is the capital and most populous city of the Netherlands, with The Hague being the seat of government. It has a population of 907,976 within the city proper, 1,558,755 in the urban area and 2,480,394 in the metropolitan area. Located in the Dutch province of North Holland, Amsterdam is colloquially referred to as the "Venice of the North", for its large number of canals, now designated a UNESCO World Heritage Site. Amsterdam was founded at the mouth of the Amstel River that was dammed to control flooding; the city's name derives from the Amstel dam. Originally a small fishing village in the late 12th century, Amsterdam became a major world port during the Dutch Golden Age of the 17th century, when the Netherlands was an economic powerhouse. Amsterdam is the leading center for finance and trade, as well as a hub of production of secular art. In the 19th and 20th centuries, the city expanded and many new neighborho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leiden
Leiden (; in English and archaic Dutch also Leyden) is a city and municipality in the province of South Holland, Netherlands. The municipality of Leiden has a population of 119,713, but the city forms one densely connected agglomeration with its suburbs Oegstgeest, Leiderdorp, Voorschoten and Zoeterwoude with 206,647 inhabitants. The Netherlands Central Bureau of Statistics (CBS) further includes Katwijk in the agglomeration which makes the total population of the Leiden urban agglomeration 270,879, and in the larger Leiden urban area also Teylingen, Noordwijk, and Noordwijkerhout are included with in total 348,868 inhabitants. Leiden is located on the Oude Rijn, at a distance of some from The Hague to its south and some from Amsterdam to its north. The recreational area of the Kaag Lakes ( Kagerplassen) lies just to the northeast of Leiden. A university city since 1575, Leiden has been one of Europe's most prominent scientific centres for more than four centuries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomer
An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either observational (by analyzing the data) or theoretical astronomy. Examples of topics or fields astronomers study include planetary science, solar astronomy, the origin or evolution of stars, or the formation of galaxies. A related but distinct subject is physical cosmology, which studies the Universe as a whole. Types Astronomers usually fall under either of two main types: observational and theoretical. Observational astronomers make direct observations of celestial objects and analyze the data. In contrast, theoretical astronomers create and investigate models of things that cannot be observed. Because it takes millions to billions of years for a system of stars or a galaxy to complete a life cycle, astronomers must observe sna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jan Woltjer (classical Scholar)
Jan Woltjer (4 February 1849, Groningen – 28 July 1917, Amsterdam) was a professor of Classical languages and literature at the Vrije Universiteit Amsterdam. Woltjer, the son of a baker, started his career as an assistant teacher at a high school in his hometown of Groningen in 1867. He taught himself Latin and managed to enter the University of Groningen in 1871. While teaching classical languages at a local gymnasium, he wrote his dissertation on Lucretius and was promoted in 1877. On 28 September that year he married Marchien Janssonius. In 1881 he moved to Amsterdam to become professor at the Free University, which position he would keep until his death in 1917. In 1902 he became member of the Royal Netherlands Academy of Arts and Sciences. He was involved in many educational organizations and was a member of the Senate for the Anti Revolutionaire Partij from 1902 to 1917. His oldest son, Robert H. Woltjer, would follow him teaching classical studies at the Free Uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Groningen (city)
Groningen (; gos, Grunn or ) is the capital city and main municipality of Groningen province in the Netherlands. The ''capital of the north'', Groningen is the largest place as well as the economic and cultural centre of the northern part of the country; as of December 2021, it had 235,287 inhabitants, making it the sixth largest city/municipality of the Netherlands and the second largest outside the Randstad. Groningen was established more than 950 years ago and gained city rights in 1245. Due to its relatively isolated location from the then successive Dutch centres of power ( Utrecht, The Hague, Brussels), Groningen was historically reliant on itself and nearby regions. As a Hanseatic city, it was part of the North German trade network, but later it mainly became a regional market centre. At the height of its power in the 15th century, Groningen could be considered an independent city-state and it remained autonomous until the French era. Today Groningen is a university ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leiden University
Leiden University (abbreviated as ''LEI''; nl, Universiteit Leiden) is a public research university in Leiden, Netherlands. The university was founded as a Protestant university in 1575 by William, Prince of Orange, as a reward to the city of Leiden for its defence against Spanish attacks during the Eighty Years' War. As the oldest institution of higher education in the Netherlands, it enjoys a reputation across Europe and the world. Known for its historic foundations and emphasis on the social sciences, the university came into particular prominence during the Dutch Golden Age, when scholars from around Europe were attracted to the Dutch Republic due to its climate of intellectual tolerance and Leiden's international reputation. During this time, Leiden became the home to individuals such as René Descartes, Rembrandt, Christiaan Huygens, Hugo Grotius, Baruch Spinoza and Baron d'Holbach. The university has seven academic faculties and over fifty subject departments wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gerard P
Gerard is a masculine forename of Proto-Germanic origin, variations of which exist in many Germanic and Romance languages. Like many other early Germanic names, it is dithematic, consisting of two meaningful constituents put together. In this case, those constituents are ''gari'' > ''ger-'' (meaning 'spear') and -''hard'' (meaning 'hard/strong/brave'). Common forms of the name are Gerard (English, Scottish, Irish, Dutch, Polish and Catalan); Gerrard (English, Scottish, Irish); Gerardo (Italian, and Spanish); Geraldo (Portuguese); Gherardo (Italian); Gherardi (Northern Italian, now only a surname); Gérard (variant forms ''Girard'' and ''Guérard'', now only surnames, French); Gearóid (Irish); Gerhardt and Gerhart/ Gerhard/ Gerhardus ( German, Dutch, and Afrikaans); Gellért ( Hungarian); Gerardas ( Lithuanian) and Gerards/Ģirts ( Latvian); Γεράρδης (Greece). A few abbreviated forms are Gerry and Jerry (English); Gerd (German) and Gert (Afrikaans and Dutch); ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lodewijk Woltjer
Lodewijk Woltjer (26 April 1930 – 25 August 2019) was an astronomer, and the son of astronomer Jan Woltjer. He studied at the University of Leiden under Jan Oort earning a PhD in astronomy in 1957 with a thesis on the Crab Nebula. This was followed by post-doctoral research appointments to various American universities and the subsequent appointment of professor of theoretical astrophysics and plasma physics in the University of Leiden. From 1964 to 1974 he was Rutherford Professor of Astronomy and Chair of the Astronomy Department at Columbia University in New York. From 1975 to 1987 he was Director General of the European Southern Observatory (ESO), where he initiated the construction of the Very Large Telescope. In 1994–1997 he was President of the International Astronomical Union. Woltjer was honored in 1987 with the Karl Schwarzschild Medal. He was the first Editor-in-Chief of The Astronomy and Astrophysics Review, inaugurated in 1989; and also the Editor of the Astronomi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Southern Observatory
The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental research organisation made up of 16 member states for ground-based astronomy. Created in 1962, ESO has provided astronomers with state-of-the-art research facilities and access to the southern sky. The organisation employs about 730 staff members and receives annual member state contributions of approximately €162 million. Its observatories are located in northern Chile. ESO has built and operated some of the largest and most technologically advanced telescopes. These include the 3.6 m New Technology Telescope, an early pioneer in the use of active optics, and the Very Large Telescope (VLT), which consists of four individual 8.2 m telescopes and four smaller auxiliary telescopes which can all work together or separately. The Atacama Large Millimeter Array observes the universe in the millimetre an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woltjer (crater)
Woltjer is an impact crater that is located in the northern latitudes of the Moon's far side. It is just attached to the southern outer rim of the larger crater Montgolfier. To the southwest is Schneller and to the east is Stoletov. It is named after astronomer Jan Woltjer. This is a relatively recent impact compared to most of the craters on the far side, and the rim is still well-formed with little erosion. It is old enough, however, that its albedo Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that refl ... matches its surroundings and it lacks a ray system. The inner wall has slumped in places and formed piles of talus along the south. The interior floor has two lines of low ridges that begin in the southeast and curve up to the northwestern inner wall. There is a level patch in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of Australia). The Moon is a planetary-mass object with a differentiated rocky body, making it a satellite planet under the geophysical definitions of the term and larger than all known dwarf planets of the Solar System. It lacks any significant atmosphere, hydrosphere, or magnetic field. Its surface gravity is about one-sixth of Earth's at , with Jupiter's moon Io being the only satellite in the Solar System known to have a higher surface gravity and density. The Moon orbits Earth at an average distance of , or about 30 times Earth's diameter. Its gravitational influence is the main driver of Earth's tides and very slowly lengthens Earth's day. The Moon's orbit around Earth has a sidereal period of 27.3 days. During each synod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1795 Woltjer
Events January–June * January – Central England records its coldest ever month, in the CET records dating back to 1659. * January 14 – The University of North Carolina opens to students at Chapel Hill, becoming the first state university in the United States. * January 16 – War of the First Coalition: Flanders campaign: The French occupy Utrecht, Netherlands. * January 18 – Batavian Revolution in Amsterdam: William V, Prince of Orange, Stadtholder of the Dutch Republic (Republic of the Seven United Netherlands), flees the country. * January 19 – The Batavian Republic is proclaimed in Amsterdam, ending the Dutch Republic (Republic of the Seven United Netherlands). * January 20 – French troops enter Amsterdam. * January 23 – Flanders campaign: Capture of the Dutch fleet at Den Helder: The Dutch fleet, frozen in Zuiderzee, is captured by the French 8th Hussars. * February 7 – The Eleventh Amendment to the United ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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