翻訳と辞書 Words near each other ・ Sigma Lambda Upsilon ・ Sigma Leonis ・ Sigma level ・ Sigma Librae ・ Sigma Lupi ・ Sigma model ・ Sigma Motor Corporation ・ Sigma Motors ・ Sigma mount ・ Sigma Mu Delta ・ Sigma Mu Sigma ・ Sigma Nu ・ Sigma Octantis ・ Sigma Omicron Pi ・ Sigma Ophiuchi ・ Sigma Orionis ・ Sigma Pegasi ・ Sigma Persei ・ Sigma Pharmaceuticals ・ Sigma Phi ・ Sigma Phi Beta ・ Sigma Phi Delta ・ Sigma Phi Epsilon ・ Sigma Phi Epsilon Literary Society ・ Sigma Phi Lambda ・ Sigma Phi Omega ・ Sigma Phi Rho ・ Sigma Pi ・ Sigma Pi (literary society) ・ Sigma Pi Alpha 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 Sigma Orionis ： ウィキペディア英語版 Sigma Orionis Sigma Orionis or Sigma Ori (σ Orionis, σ Ori) is a five-star system in the constellation Orion, just to the southwest of Alnitak. It is approximately 1,150 light years from Earth. The primary component is the binary Sigma Orionis AB, with the two stars being a mere 0.25 arcseconds apart. Both stars are hydrogen-fusing dwarfs only a few million years old. The brighter one, Sigma Orionis A, is a blue O-type star with an apparent visual magnitude of +4.2. Sigma Orionis B is a B-type star with an apparent visual magnitude of +5.1. The pair orbit each other every 170 years at a distance of about 90 AU. A and B have very hot surfaces, around 32,000 and 29,600 kelvins, radiating at about 35,000 and 30,000 solar luminosities, respectively. Temperature and luminosity give masses of 18 and 13.5 solar masses, making the close AB pair among the most massive of visual binaries. The next brightest stars in the system are Sigma Orionis D and E, which lie about 4,600 and 15,000 AU respectively from the AB pair. Both are seven solar mass B-type dwarf stars with magnitudes of 6.62 and 6.66. Sigma Orionis E is a prototype of the strange "helium-rich" stars, which have significantly large amounts of helium. The last star in the system is Sigma Orionis C, an A-type dwarf star. C is the closest to the AB pair, about 3,900 AU away. ==References== 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「Sigma Orionis」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.