翻訳と辞書 Words near each other ・ Epsilon (rocket) ・ Epsilon (text editor) ・ Epsilon (wasp) ・ Epsilon 15 ・ Epsilon Andromedae ・ Epsilon antitoxin ・ Epsilon Antliae ・ Epsilon Apodis ・ Epsilon Aquarii ・ Epsilon Aquilae ・ Epsilon Arae ・ Epsilon Arietis ・ Epsilon Aurigae ・ Epsilon Award ・ Epsilon axe ・ Epsilon Boötis ・ Epsilon calculus ・ Epsilon Cancri ・ Epsilon Canis Majoris ・ Epsilon Canis Minoris ・ Epsilon Capricorni ・ Epsilon Carinae ・ Epsilon Cassiopeiae ・ Epsilon cell ・ Epsilon Centauri ・ Epsilon Cephei ・ Epsilon Ceti ・ Epsilon Chamaeleontis ・ Epsilon Circini ・ Epsilon Columbae Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Epsilon Boötis ： ウィキペディア英語版 Epsilon Boötis Epsilon Boötis (ε Boo, ε Boötis) is a double star in the northern constellation of Boötes. It has the traditional name Izar and was named Pulcherrima (most beautiful) by Otto Struve.〔Norton's Star Atlas, publ. Gall & Inglis, Edinburgh, 2nd Ed., 1959〕 The star system can be viewed with the unaided eye at night, but resolving the pair with a small telescope is challenging; an aperture of or greater is required.〔 ==Properties== Epsilon Boötis consists of a pair of stars with an angular separation of at a position angle of .〔 The brighter component (A) has an apparent visual magnitude of 2.37,〔 making it readily visible to the naked eye at night. The fainter component (B) is at magnitude 5.12,〔 which by itself would also be visible to the naked eye. Parallax measurements from the Hipparcos astrometry satellite〔〔 put the system at a distance of about from the Earth.〔 This means the pair has a projected separation of 185 Astronomical Units and they orbit each other with a period of at least 1,000 years.〔 The brighter member has a stellar classification of K0 II-III,〔 which means it is a fairly late-stage star well into its stellar evolution, having already exhausted its supply of hydrogen fuel at the core. With more than four times the mass of the Sun,〔 it has expanded to about 33 times the Sun's radius and is emitting 501 times the luminosity of the Sun.〔 This energy is being radiated from its outer envelope at an effective temperature of 4,550 K,〔 giving it the orange hue of a K-type star.〔 The companion star has a classification of A2 V,〔 so it is a main sequence star that is generating energy through the thermonuclear fusion of hydrogen at its core. This star is rotating rapidly, with a projected rotational velocity of 〔 By the time the smaller main sequence star reaches the current point of the primary in its evolution, the larger star will have lost much of its mass in a planetary nebula and will have evolved into a white dwarf. The pair will have essentially changed roles: the brighter star becoming the dim dwarf, while the lesser companion will shine as a giant 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「Epsilon Boötis」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.