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Summer Triangle
The Summer Triangle is an astronomical asterism in the northern celestial hemisphere. The defining vertices of this imaginary triangle are at Altair, Deneb, and Vega, each of which is the brightest star of its constellation ( Aquila, Cygnus, and Lyra, respectively). The greatest declination is +45° and lowest is +9° meaning the three can be seen from all places in the Northern Hemisphere and from the home of most people resident in the Southern Hemisphere. The two stars in Aquila and Cygnus represent the head of an eagle and tail of a swan that looks east inscribed into the triangle and forming the altitude of the triangle. Two small constellations, Sagitta and Vulpecula, lie between Aquila in the south of the triangle and Cygnus and Lyra to the north. History The term was popularized by the American author H. A. Rey and the British astronomer Patrick Moore in the 1950s. The name can be found in constellation guidebooks as far back as 1913. The Austrian astronomer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquila (constellation)
Aquila is a constellation on the celestial equator. Its name is Latin for 'eagle' and it represents the bird that carried Zeus/Jupiter's thunderbolts in Greco-Roman mythology, Greek-Roman mythology. Its brightest star, Altair, is one vertex of the Summer Triangle asterism (astronomy), asterism. The constellation is best seen in the northern summer, as it is located along the Milky Way. Because of this location, many clusters and planetary nebula, nebulae are found within its borders, but they are dim and galaxies are few. History Aquila was one of the 48 constellations described by the second-century astronomer Ptolemy. It had been earlier mentioned by Eudoxus of Cnidus, Eudoxus in the fourth century BC and Aratus in the third century BC. It is now one of the 88 constellations defined by the International Astronomical Union. The constellation was also known as ''Vultur volans'' (the flying vulture) to the Ancient Rome, Romans, not to be confused with ''Vultur cadens'' which wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altair
Altair is the brightest star in the constellation of Aquila (constellation), Aquila and the list of brightest stars, twelfth-brightest star in the night sky. It has the Bayer designation Alpha Aquilae, which is Latinisation of names, Latinised from α Aquilae and abbreviated Alpha Aql or α Aql. Altair is an A-type main-sequence star, A-type main-sequence star with an apparent visual magnitude of 0.77 and is one of the vertices of the Summer Triangle Asterism (astronomy), asterism; the other two vertices are marked by Deneb and Vega. It is located at a distance of from the Sun. Altair is currently in the G-cloud—a nearby interstellar cloud formed from an accumulation of gas and dust. Altair rotates rapidly, with a velocity at the equator of approximately 286 km/s.From values of ''v'' sin ''i'' and ''i'' in the second column of Table 1, Monnier et al. 2007. This is a significant fraction of the star's estimated breakup speed of 400 km/s. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Johann Von Littrow
Joseph Johann von Littrow (13 March 1781, Horšovský Týn () – 30 November 1840, Vienna) was an Austrian astronomer. In 1837, he was ennobled with the title Joseph Johann Edler von Littrow. He was the father of Karl Ludwig Edler von Littrow and the mentor of the mathematician Nikolai Brashman. His work took him to Russia for a time, which is where his son who succeeded him was born. He became director of the Vienna Observatory in 1819. He served in this position until his death in 1840. He created the only conformal retroazimuthal map projection, which is known as the Littrow projection. Littrow authored the widely read ''Wunder des Himmels'' ("Miracles of the Sky"), which was reprinted eight times by 1897. Von Littrow is often associated with a proposal to dig a large circular canal in the Sahara desert and fill it with burning kerosene, thus communicating the fact of human intelligence to aliens who may be observing Earth. However, Von Littrow's connection with this sch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zenith
The zenith (, ) is the imaginary point on the celestial sphere directly "above" a particular location. "Above" means in the vertical direction (Vertical and horizontal, plumb line) opposite to the gravity direction at that location (nadir). The zenith is the "highest" point on the celestial sphere. The direction opposite of the zenith is the nadir. Origin The word ''zenith'' derives from an inaccurate reading of the Arabic language, Arabic expression (), meaning "direction of the head" or "path above the head", by Medieval Latin scribes in the Middle Ages (during the 14th century), possibly through Old Spanish. It was reduced to ''samt'' ("direction") and miswritten as ''senit''/''cenit'', the ''m'' being misread as ''ni''. Through the Old French ''cenith'', ''zenith'' first appeared in the 17th century. Relevance and use The term ''zenith'' sometimes means the culmination, highest point, way, or level reached by a celestial body on its daily apparent path around a given poi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined by humans as being in the same celestial sphere, celestial hemisphere relative to the invariable plane of the Solar System as Earth's North Pole. Due to Earth's axial tilt of 23.439281°, there is a seasonal variation in the lengths of the day and night. There is also a seasonal variation in temperatures, which lags the variation in day and night. Conventionally, winter in the Northern Hemisphere is taken as the period from the December solstice (typically December 21 UTC) to the March equinox (typically March 20 UTC), while summer is taken as the period from the June solstice through to the September equinox (typically on 23 September UTC). The dates vary each year due to the difference between the calendar year and the Year#Astronomical years, astronomical year. Within the Northern Hemisphere, oceanic currents can change the weather patterns that aff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Latitudes
The middle latitudes, also called the mid-latitudes (sometimes spelled midlatitudes) or moderate latitudes, are spatial regions on either Hemispheres of Earth, hemisphere of Earth, located between the Tropic of Cancer (latitude ) and the Arctic Circle () in the northern hemisphere and between the Tropic of Capricorn (-) and the Antarctic Circle (-) in the southern hemisphere. They include Earth's subtropics, subtropical and temperate climate, temperate zones, which lie between the two tropics and the polar circles. Weather fronts and extratropical cyclones are usually found in this area, as well as occasional tropical cyclones or subtropical cyclones, which have traveled from their areas of formation closer to the Equator. The prevailing winds in the middle latitudes are often very strong. These parts of the world also see a wide variety of fast-changing weather as cold air masses from the poles and warm air masses from the tropics constantly push up and down over them against e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altaïr Vega & Deneb
The ''Assassin's Creed'' media franchise, which primarily consists of a series of Open world, open-world action-adventure game, action-adventure Stealth game, stealth video games published by Ubisoft, features an extensive cast of characters in its historical fiction and science fiction-based narratives. The series also encompasses a wide variety of media outside of video games, including novels, comic books, board games, animated films, a Assassin's Creed (film), live-action film, and an upcoming Netflix television series. The series features original characters intertwined with real-world historical events and historical figures, figures, and is centered on a fictional millennia-old struggle for peace between the Assassin Brotherhood, inspired by the real-life Order of Assassins, who fight for peace and free will and embody the concept of chaos; and the Knights Templar in popular culture, Templar Order, inspired by the real-life Knights Templar, who desire peace through contro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AuthorHouse
AuthorHouse, formerly known as 1stBooks, is a self-publishing company based in the United States. AuthorHouse uses print-on-demand business model and technology. History Originally called 1stBooks, the company was founded in Bloomington, Indiana, United States, in January 1997. Its first e-book appeared in June of that year. In January 1999, it started using print-on-demand technology to produce paper books. The AuthorHouse website states the company has published over 70,000 titles by 50,000 authors since 1997. The company opened an office in Milton Keynes, United Kingdom, in May 2004. In October 2005, AuthorHouse was nominated by the Indiana Chamber of Commerce for the Small Business of the Year Award. AuthorHouse won the Silver Award under the Service industry category. The US investment group Bertram Capital purchased AuthorHouse in 2007 from Gazelle TechVentures, which had owned AuthorHouse since 2002. Later in 2007, Bertram established Author Solutions and acquired A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Air Force
The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its origins to 1 August 1907, as a part of the United States Army Signal Corps, the USAF was established by transfer of personnel from the Army Air Forces with the enactment of the National Security Act of 1947. It is the second youngest branch of the United States Armed Forces and the fourth in United States order of precedence, order of precedence. The United States Air Force articulates its core missions as air supremacy, intelligence, surveillance, target acquisition, and reconnaissance, global integrated intelligence, surveillance and reconnaissance, airlift, rapid global mobility, Strategic bombing, global strike, and command and control. The United States Department of the Air Force, Department of the Air Force, which serves as the USAF's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inertial Navigation System
An inertial navigation system (INS; also inertial guidance system, inertial instrument) is a navigation device that uses motion sensors (accelerometers), rotation sensors (gyroscopes) and a computer to continuously calculate by dead reckoning the position, the orientation, and the velocity (direction and speed of movement) of a moving object without the need for external references. Often the inertial sensors are supplemented by a barometric altimeter and sometimes by magnetic sensors (magnetometers) and/or speed measuring devices. INSs are used on mobile robots and on vehicles such as ships, aircraft, submarines, guided missiles, and spacecraft. Older INS systems generally used an inertial platform as their mounting point to the vehicle and the terms are sometimes considered synonymous. Design Inertial navigation is a self-contained navigation technique in which measurements provided by accelerometers and gyroscopes are used to track the position and orientation of an object ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chilseok
Chilseok () is a Korean traditional festival which falls on the seventh day of the seventh month of the Korean lunisolar calendar, originating from the Chinese Qixi Festival. Chilseok is a period where the heat starts to dwindle and the Wet season begins, and the rain that falls during this period is called Chilseok water. As pumpkins, cucumbers, and melons start to flourish during this period, people traditionally offered fried pumpkins to the Big Dipper. The story of Chilseok The origin of the tale is a romantic Chinese folk tale, The Cowherd and the Weaver Girl. It was adopted by Koreans. According to the Korean version, a heavenly king had a daughter called Jiknyeo (), who was a talented weaver. One day, when she looked out of the window while weaving, she saw a young man, a herder called Gyeonu (), just across the Milky Way, and fell in love with him; the father allowed the two to marry. Afterwards, Jiknyeo refused to weave clothes, and Gyeonu did not take good care of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
