|
Eta Ceti (η Cet, η Ceti) is a star in the equatorial constellation of Cetus, the whale. It has the traditional name Deneb Algenubi or Algenudi. The apparent visual magnitude of this star is +3.4,〔 making it the fourth brightest star in this otherwise relatively faint constellation. The distance to this star can be measured directly using the parallax technique, yielding a value of .〔 This is a giant star with a stellar classification of K1 III,〔 having exhausted the hydrogen at its core and evolved away from the main sequence of stars like the Sun. (The classification is sometimes listed as K1.5 IIICN1Fe0.5, indicating a higher than normal abundance of cyanogen and iron relative to other stars of its class.)〔 It is a red clump star that is generating energy through the nuclear fusion of helium at its core.〔 Eta Ceti may have slightly more mass than the Sun and its outer envelope has expanded to 15 times the Sun's radius.〔 It is radiating 74〔 times as much luminosity as the Sun from its outer atmosphere at an effective temperature of 4,356 K.〔 This heat gives the star the orange-hued glow of a K-type star.〔 ==In culture== The name ''Deneb Algenubi'' was from Arabic ذنب ألجنبي - ''ðánab al-janūbii'', meaning ''the southern tail of the sea monster''. In the catalogue of stars in the ''Calendarium'' of Al Achsasi al Mouakket, this star was designated Aoul al Naamat (أول ألنعمة - ''awwil al naʽāmāt''), which was translated into Latin as Prima Struthionum, meaning ''the first ostrich''.〔 This star, along with θ Cet (Thanih al Naamat), τ Cet (Thalath Al Naamat), ζ Cet (Baten Kaitos) and υ Cet, were Al Naʽāmāt (ألنعمة), the Hen Ostriches.〔〔 In Chinese, (), meaning ''Square Celestial Granary'', refers to an asterism consisting of η Ceti, ι Ceti, θ Ceti, ζ Ceti, τ Ceti and 57 Ceti.〔 ''中國星座神話'', written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.〕 Consequently, η Ceti itself is known as (, (英語:the Second Star of Square Celestial Granary).)〔 (香港太空館 - 研究資源 - 亮星中英對照表 ), Hong Kong Space Museum. Accessed on line November 23, 2010.〕 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「Eta Ceti」の詳細全文を読む スポンサード リンク
|