翻訳と辞書
Words near each other
・ Aldeanueva de la Sierra
・ Aldeanueva de la Vera
・ Aldeanueva de San Bartolomé
・ Aldeanueva de Santa Cruz
・ Aldeanueva del Camino
・ Aldeanueva del Codonal
・ Aldeaquemada
・ Aldearrodrigo
・ Aldearrubia
・ Aldeaseca
・ Aldeaseca de Alba
・ Aldeaseca de la Frontera
・ Aldeasoña
・ Aldeatejada
・ Aldeavieja de Tormes
Aldebaran
・ Aldebaran (comics)
・ Aldebaran (disambiguation)
・ Aldebaran (film)
・ Aldebaran (rocket)
・ Aldebaran b
・ Aldebaran in fiction
・ Aldebert
・ Aldeboarn
・ Aldebrandus
・ Aldeburgh
・ Aldeburgh (UK Parliament constituency)
・ Aldeburgh Branch Line
・ Aldeburgh Cinema
・ Aldeburgh Cottage Hospital


Dictionary Lists
翻訳と辞書 辞書検索 [ 開発暫定版 ]
スポンサード リンク

Aldebaran : ウィキペディア英語版
Aldebaran


Aldebaran 〔(Oxford Dictionary: Aldebaran )〕〔(Merriam-Webster: Aldebaran )〕 (α Tau, α Tauri, Alpha Tauri) is an orange giant star located about 65 light years away in the zodiac constellation of Taurus. With an average apparent magnitude of 0.87 it is the brightest star in the constellation and is one of the brightest stars in the nighttime sky. The name ''Aldebaran'' is Arabic ( ') and means "the Follower", presumably because it rises near and soon after the Pleiades.
In 1993 a substellar companion was reported. Subsequent observations did not confirm this claim, but a paper accepted for publication in Astronomy and Astrophysics in 2015 shows evidence for a planetary companion.
The planetary exploration probe Pioneer 10 is currently heading in the general direction of the star and should make its closest approach in about two million years.〔
==Observation history==

In March of 509 CE, a lunar occultation of Aldebaran was observed in Athens, Greece. English astronomer Edmund Halley studied the timing of this event, and in 1718 concluded that Aldebaran must have changed position since that time, moving several minutes of arc further to the north. This, as well as observations of the changing positions of stars Sirius and Arcturus, led to the discovery of proper motion. Based on present day observations, the position of Aldebaran has shifted 7′ in the last 2000 years; roughly a quarter the diameter of the full Moon.
English astronomer William Herschel discovered a faint companion to Aldebaran in 1782;〔 an 11th magnitude star at an angular separation of 117. This star was shown to be itself a close double star by S. W. Burnham in 1888, and he discovered an additional 14th magnitude companion at an angular separation of 31″. Follow on measurements of proper motion showed that Herschel's companion was diverging from Aldebaran, and hence they were not physically connected. However, the companion discovered by Burnham had almost exactly the same proper motion as Aldebaran, suggesting that the two formed a wide binary star system.
Working at his private observatory in Tulse Hill, England, in 1864 William Huggins performed the first studies of the spectrum of Aldebaran, where he was able to identify the lines of nine elements, including iron, sodium, calcium, and magnesium. In 1886, Edward C. Pickering at the Harvard College Observatory used a photographic plate to capture fifty absorption lines in the spectrum of Aldebaran. This became part of the Draper Catalogue, published in 1890. By 1887, the photographic technique had improved to the point that it was possible to measure a star's radial velocity from the amount of Doppler shift in the spectrum. By this means, the recession velocity of Aldebaran was estimated as (48 km/s), using measurements performed at Potsdam Observatory by Hermann C. Vogel and his assistant Julius Scheiner.
The angular diameter of this star was measured for the first time in 1921 using an interferometer attached to the Hooker Telescope at the Mount Wilson Observatory. The result was 0.0237″, which was in close agreement with the estimated values of the time.

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「Aldebaran」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.