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The planetary systems of stars other than the Sun and the Solar System are a staple element in much science fiction. ==The Star Deneb== (詳細はsupergiant of spectral type A2Ia〔(【引用サイトリンク】work=The Dome of the Sky )〕 in the constellation Cygnus, shines prominently in the night sky—despite its lying at the inordinate distance of some 1550 light-years—and it is frequently employed as a remote location, faraway destination, or alien home sun in works of fiction (see "Dead Ahead" by Jack Vance and ''The Rowan'' by Anne McCaffrey, below). Deneb's absolute magnitude is approximately −7.0, one of the greatest intrinsic brightnesses of any known star, which gives it an estimated luminosity nearly 60,000 times that of our Sun (see "Uncommon Sense" by Hal Clement, below). It appears to have a diameter of about 110 times that of the Sun (see graphic), but a mass only 20 times as great〔—bespeaking a tenuous average density approximately 10−5 times that of our own star. The classification of Deneb as a blue-white supergiant, its mass (~20 solar masses, ), and its surface temperature (~8400 K) mean that the star will enjoy but a short lifespan and probably go supernova within a few million years. Its stellar wind causes it to lose mass at a rate of 8×10−7 /yr, a hundred thousand times the flow rate from the Sun. Deneb is the brightest star in the constellation Cygnus and the nineteenth brightest star in the night sky, with an apparent visual magnitude of 1.25. It is a vertex of the Summer Triangle, the other two vertices being the bright stars Altair and Vega (see ''High Sierra'', below).〔(【引用サイトリンク】work=The Internet Encyclopedia of Science )〕 The name Deneb is from the Arabic (ذنب الدجاجة dhanab ad-dajājah), which translates literally as tail of the hen. In Chinese, "天津" (Tiān Jīn), meaning ''Celestial Ford'', refers to an asterism consisting of Deneb and eight other stars in Cygnus (see graphic, below). In a legendary Chinese love story, Deneb marks the location of the ''magpie bridge'' across the Milky Way,〔(【引用サイトリンク】work=The Internet Encyclopedia of Science )〕 which allows two lovers represented by the stars Altair and Vega—the other two vertices of the Summer Triangle—to be reunited on one special night of the year in late summer (See Qi Xi, below). 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「Deneb in fiction」の詳細全文を読む スポンサード リンク
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