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Altarf (β Cnc, β Cancri, Tarf, Al Tarf) is the brightest star in the zodiacal constellation Cancer. At approximately 290 light years from earth, it has an apparent magnitude of +3.50 and absolute magnitude of -1.25 (visual).〔 The star is an orange K-type giant, about 48 times the radius of the Sun.〔 The traditional name ''Tarf'' or ''Al Tarf'' (anglicized as ''Altarf''), can be translated from Arabic as "end" or "edge".〔 Altarf is known to have a fourteenth magnitude, red dwarf companion star. From its angular distance of 29 arcseconds, the companion's distance from its parent star is estimated at some 2600 AU, and has an orbital period of 76,000 years.〔 In a paper published in the journal ''Astronomy & Astrophysics'' on May 12, 2014, evidence was presented of a planet orbiting Altarf. Using radial velocity data from repeated observations of the star, the planet is estimated to have a minimum mass of approximately 7.8 times that of Jupiter, and an orbit of 605 days.〔 ==See also== * Lists of stars in the constellation Cancer * Class K Stars * Barium star 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「Altarf」の詳細全文を読む スポンサード リンク
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