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 equinox (celestial coordinates), March equinox to the (hour circle of the) point in question above the Earth. When paired with declination, these celestial coordinate system, astronomical coordinates specify the location of a point on the celestial sphere in the equatorial coordinate system. An old term, ''right ascension'' (), "''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 perpendicular, intersects the horizon at a right angle. It contrasts wi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Hour
An hour (symbol: h; also abbreviated hr) is a unit of time historically reckoned as of a day and defined contemporarily as exactly 3,600 seconds ( SI). There are 60 minutes in an hour, and 24 hours in a day. The hour was initially established in the ancient Near East as a variable measure of of the night or daytime. Such seasonal hours, also known as temporal hours or unequal hours, varied by season and latitude. Equal hours or equinoctial hours were taken as of the day as measured from noon to noon; the minor seasonal variations of this unit were eventually smoothed by making it of the mean solar day. Since this unit was not constant due to long term variations in the Earth's rotation, the hour was finally separated from the Earth's rotation and defined in terms of the atomic or physical second. It is a non-SI unit that is accepted for use with SI. In the modern metric system, one hour is defined as 3,600 atomic seconds. However, on rare occasions an hour may inc ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Oh (other)
Oh, OH, or Oh! is an interjection, often proclaiming surprise. It may refer to: Arts and entertainment Music Albums * ''Oh!'' (Girls' Generation album), 2010 * ''Oh!'' (ScoLoHoFo album), 2003 * ''OH (ohio)'', by Lambchop, 2008 * ''Oh!'', an EP that came with the preorders of ''Oh! Gravity.'' by Switchfoot, 2006 Songs * " O (Oh!)", 1920 by Ted Lewis, 1953 by Pee Wee Hunt * "Oh" (Ciara song), 2005 * "Oh!" (Girls' Generation song), 2010 * "Oh!" (The Linda Lindas song), 2021 * "Oh!" (Pink Lady song), 1981 * "Oh" (Stray Kids song), 2021 * "Oh!", by Boys Noize from '' Oi Oi Oi'' * "Oh!", by The Breeders from '' Pod'' * "Oh", by Dave Matthews from '' Some Devil'' * "Oh", by Fugazi from '' The Argument'' * "Oh", by Juliana Hatfield from ''Made in China'' * "Oh!", by Micky Green from ''White T-Shirt'' * "Oh!", by Sleater-Kinney from '' One Beat'' * "Oh", by Spratleys Japs from ''Pony'' * "Oh!", by The Trudy * "Oh," by Underworld, recorded for the soundtrack to A Life Less Ord ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |