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Altair (Alpha Aquilae) is a luminous white star in the constellation Aquila (the Eagle) frequently featured in works of science fiction. ==Star== Classified as an A-type main sequence star, and located 16.7 light-years from Earth, Altair is one of the few stars for which a resolved image of measurable nonzero extent has been obtained〔(【引用サイトリンク】work=National Science Foundation )〕 (see graphic〔This image of Altair was made in 2006 with infrared interferometry, using the MIRC instrument on the CHARA array interferometer, and published in 2007 by J. D. Monnier and his coworkers at the Mount Wilson Observatory.〕). It rotates so rapidly, with a period of just 9 hours – compared to 25 days for the Sun – that it is significantly oblate, having an equatorial diameter more than 20 percent greater than its polar diameter. It is a peculiar fact that among the authors of the fictional works in this article, not excluding Hal Clement (who imagined dramatic equatorial bulges for many of his ''planets''), only Jerry Oltion (1999) has employed or even acknowledged the striking physical peculiarities of this star (see "Biosphere", below). There is no evidence that the system is home to any extrasolar planets. Altair is the brightest star in the constellation Aquila and the twelfth brightest star in the night sky. With an apparent visual magnitude of 0.77, it is one of the closest stars visible to the unaided eye (most of the nearest stars are red dwarfs too dim to see without a telescope). It forms a part of two well-known triplet asterisms: With β and γ Aquilae it forms the straight line of stars sometimes referred to as the ''Family of Aquila'' or the ''Shaft of Aquila''; more prominently, it is the southernmost vertex of the Summer Triangle, the other two vertices being the bright stars Deneb and Vega (see ''High Sierra'', below).〔(【引用サイトリンク】work=The Internet Encyclopedia of Science )〕 The name Altair is from the Arabic (النسر الطائر ''an-nasr aṭ-ṭā’ir''), which translates literally as ''the flying eagle'', from its belonging to the constellation. The star is named and plays a part in a variety of ancient myths worldwide, especially in the Western- and South-Pacific regions of the globe. In particular, in Chinese myth it is called the ''Cowherd Star'' after the story of the cowherd Niú Láng and his two children (β and γ Aquilae), who are separated from their mother Zhī Nŭ (the star Vega) by the Milky Way. They are only permitted to meet once a year, when the Milky Way is crossed by a bridge of magpies. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Altair in fiction」の詳細全文を読む スポンサード リンク
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