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Colure
Colure, in astronomy, is either of the two principal meridians of the celestial sphere. Equinoctial colure The ''equinoctial colure'' is the meridian or great circle of the celestial sphere which passes through the celestial poles and the two equinoxes: the first point of Aries and the first point of Libra. Solstitial colure The ''solstitial colure'' is the meridian or great circle of the celestial sphere which passes through the poles and the two solstices: the first point of Cancer and the first point of Capricorn. There are several stars closely aligned with the solstitial colure: Pi Herculis, Delta Aurigae, and Theta Scorpii. This makes the solstitial colure point towards the North Celestial Pole and Polaris. See also * Celestial coordinate system * Ecliptic * Celestial sphere * Right ascension * Equinox * Solstice A solstice is an event that occurs when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colure
Colure, in astronomy, is either of the two principal meridians of the celestial sphere. Equinoctial colure The ''equinoctial colure'' is the meridian or great circle of the celestial sphere which passes through the celestial poles and the two equinoxes: the first point of Aries and the first point of Libra. Solstitial colure The ''solstitial colure'' is the meridian or great circle of the celestial sphere which passes through the poles and the two solstices: the first point of Cancer and the first point of Capricorn. There are several stars closely aligned with the solstitial colure: Pi Herculis, Delta Aurigae, and Theta Scorpii. This makes the solstitial colure point towards the North Celestial Pole and Polaris. See also * Celestial coordinate system * Ecliptic * Celestial sphere * Right ascension * Equinox * Solstice A solstice is an event that occurs when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solstice
A solstice is an event that occurs when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around June 21 and December 21. In many countries, the seasons of the year are determined by the solstices and the equinoxes. The term ''solstice'' can also be used in a broader sense, as the day when this occurs. The day of a solstice in either hemisphere has either the most sunlight of the year ( summer solstice) or the least sunlight of the year (winter solstice) for any place other than the Equator. Alternative terms, with no ambiguity as to which hemisphere is the context, are " June solstice" and " December solstice", referring to the months in which they take place every year. The word ''solstice'' is derived from the Latin ''sol'' ("sun") and ''sistere'' ("to stand still"), because at the solstices, the Sun's declination appears to "stand still"; that is, the seasonal move ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solstice
A solstice is an event that occurs when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around June 21 and December 21. In many countries, the seasons of the year are determined by the solstices and the equinoxes. The term ''solstice'' can also be used in a broader sense, as the day when this occurs. The day of a solstice in either hemisphere has either the most sunlight of the year ( summer solstice) or the least sunlight of the year (winter solstice) for any place other than the Equator. Alternative terms, with no ambiguity as to which hemisphere is the context, are " June solstice" and " December solstice", referring to the months in which they take place every year. The word ''solstice'' is derived from the Latin ''sol'' ("sun") and ''sistere'' ("to stand still"), because at the solstices, the Sun's declination appears to "stand still"; that is, the seasonal move ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First Point Of Cancer
A solstice is an event that occurs when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around June 21 and December 21. In many countries, the seasons of the year are determined by the solstices and the equinoxes. The term ''solstice'' can also be used in a broader sense, as the day when this occurs. The day of a solstice in either hemisphere has either the most sunlight of the year ( summer solstice) or the least sunlight of the year (winter solstice) for any place other than the Equator. Alternative terms, with no ambiguity as to which hemisphere is the context, are "June solstice" and " December solstice", referring to the months in which they take place every year. The word ''solstice'' is derived from the Latin ''sol'' ("sun") and ''sistere'' ("to stand still"), because at the solstices, the Sun's declination appears to "stand still"; that is, the seasonal moveme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First Point Of Capricorn
A solstice is an event that occurs when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around June 21 and December 21. In many countries, the seasons of the year are determined by the solstices and the equinoxes. The term ''solstice'' can also be used in a broader sense, as the day when this occurs. The day of a solstice in either hemisphere has either the most sunlight of the year ( summer solstice) or the least sunlight of the year (winter solstice) for any place other than the Equator. Alternative terms, with no ambiguity as to which hemisphere is the context, are "June solstice" and " December solstice", referring to the months in which they take place every year. The word ''solstice'' is derived from the Latin ''sol'' ("sun") and ''sistere'' ("to stand still"), because at the solstices, the Sun's declination appears to "stand still"; that is, the seasonal moveme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Right Ascension
Right ascension (abbreviated RA; symbol ) is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the March equinox to the (hour circle of the) point in question above the earth. When paired with declination, these astronomical coordinates specify the location of a point on the celestial sphere in the equatorial coordinate system. An old term, ''right ascension'' ( la, ascensio recta), "''Ascensio recta'' Solis, stellæ, aut alterius cujusdam signi, est gradus æquatorus cum quo simul exoritur in sphæra recta"; roughly translated, "''Right ascension'' of the Sun, stars, or any other sign, is the degree of the equator that rises together in a right sphere" refers to the ''ascension'', or the point on the celestial equator that rises with any celestial object as seen from Earth's equator, where the celestial equator intersects the horizon at a right angle. It contrasts with ''oblique ascension'', the point on the celestial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Circle
In mathematics, a great circle or orthodrome is the circular intersection of a sphere and a plane passing through the sphere's center point. Any arc of a great circle is a geodesic of the sphere, so that great circles in spherical geometry are the natural analog of straight lines in Euclidean space. For any pair of distinct non- antipodal points on the sphere, there is a unique great circle passing through both. (Every great circle through any point also passes through its antipodal point, so there are infinitely many great circles through two antipodal points.) The shorter of the two great-circle arcs between two distinct points on the sphere is called the ''minor arc'', and is the shortest surface-path between them. Its arc length is the great-circle distance between the points (the intrinsic distance on a sphere), and is proportional to the measure of the central angle formed by the two points and the center of the sphere. A great circle is the largest circle that c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celestial Coordinate System
Astronomical coordinate systems are organized arrangements for specifying positions of satellites, planets, stars, galaxies, and other celestial objects relative to physical reference points available to a situated observer (e.g. the true horizon and north cardinal direction to an observer situated on the Earth's surface). Coordinate systems in astronomy can specify an object's position in three-dimensional space or plot merely its direction on a celestial sphere, if the object's distance is unknown or trivial. Spherical coordinates, projected on the celestial sphere, are analogous to the geographic coordinate system used on the surface of Earth. These differ in their choice of fundamental plane, which divides the celestial sphere into two equal hemispheres along a great circle. Rectangular coordinates, in appropriate units, have the same fundamental () plane and primary (-axis) direction, such as a rotation axis. Each coordinate system is named after its choice of fundamental ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Princeton University Press
Princeton University Press is an independent publisher with close connections to Princeton University. Its mission is to disseminate scholarship within academia and society at large. The press was founded by Whitney Darrow, with the financial support of Charles Scribner, as a printing press to serve the Princeton community in 1905. Its distinctive building was constructed in 1911 on William Street in Princeton. Its first book was a new 1912 edition of John Witherspoon's ''Lectures on Moral Philosophy.'' History Princeton University Press was founded in 1905 by a recent Princeton graduate, Whitney Darrow, with financial support from another Princetonian, Charles Scribner II. Darrow and Scribner purchased the equipment and assumed the operations of two already existing local publishers, that of the ''Princeton Alumni Weekly'' and the Princeton Press. The new press printed both local newspapers, university documents, ''The Daily Princetonian'', and later added book publishing to it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Chicago Press
The University of Chicago Press is the largest and one of the oldest university presses in the United States. It is operated by the University of Chicago and publishes a wide variety of academic titles, including ''The Chicago Manual of Style'', numerous academic journals, and advanced monographs in the academic fields. One of its quasi-independent projects is the BiblioVault, a digital repository for scholarly books. The Press building is located just south of the Midway Plaisance on the University of Chicago campus. History The University of Chicago Press was founded in 1890, making it one of the oldest continuously operating university presses in the United States. Its first published book was Robert F. Harper's ''Assyrian and Babylonian Letters Belonging to the Kouyunjik Collections of the British Museum''. The book sold five copies during its first two years, but by 1900 the University of Chicago Press had published 127 books and pamphlets and 11 scholarly journals, includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomy
Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest include planets, natural satellite, moons, stars, nebulae, galaxy, galaxies, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond atmosphere of Earth, Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Babylonian astronomy, Babylonians, Greek astronomy, Greeks, Indian astronomy, Indians, Egyptian astronomy, Egyptians, Chinese astronomy, Chinese, Maya civilization, Maya, and many anc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equinox
A solar equinox is a moment in time when the Sun crosses the Earth's equator, which is to say, appears directly above the equator, rather than north or south of the equator. On the day of the equinox, the Sun appears to rise "due east" and set "due west". This occurs twice each year, around 20 March and 23 September. More precisely, an equinox is traditionally defined as the time when the plane of Earth's equator passes through the geometric center of the Sun's disk. Equivalently, this is the moment when Earth's rotation axis is directly perpendicular to the Sun-Earth line, tilting neither toward nor away from the Sun. In modern times, since the Moon (and to a lesser extent the planets) causes Earth's orbit to vary slightly from a perfect ellipse, the equinox is officially defined by the Sun's more regular ecliptic longitude rather than by its declination. The instants of the equinoxes are currently defined to be when the apparent geocentric longitude of the Sun is 0° a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
