翻訳と辞書 Words near each other ・ R P S Inter College ・ R Pictoris ・ R Plus ・ R Plus Seven ・ R Prasad ・ R R Educational Trust College of Education and Research (BEd College). ・ R Ramakrishna ・ R rating ・ R Reticuli ・ R road ・ R rotunda ・ R S College of Management & Science ・ R S McLaughlin Collegiate and Vocational Institute ・ R S Wadia ・ R S Wilshere ・ R Sagittae ・ R score ・ R Sculptoris ・ R Scuti ・ R Serpentis ・ R Sri Kumar ・ R Star ・ R Street Institute ・ R Systems International ・ R Tamil Selvan ・ R Train ・ R Trianguli Australis ・ R TV Network ・ R type carriage ・ R U Crazy 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 R Sagittae ： ウィキペディア英語版 R Sagittae R Sagittae is an RV Tauri variable star in the constellation Sagitta that varies from magnitude 8.0 to 10.5 in 70.77 days. It is a post-AGB low mass yellow supergiant that varies between spectral types G0Ib and G8Ib as it pulsates. Its variable star designation of "R" indicates that it was the first star discovered to be variable in the constellation. It was discovered in 1859 by Joseph Baxendell, though classified as a semi regular variable until RV Tauri variables were identified as a distinct class in 1905. R Sagittae is classified as an RV Tauri variable because of the distinctive regular variations with alternating deep and shallow minima. The period is conventionally quoted as the time between two deep minima and is the fundamental pulsation mode. The shallow minimum is the result of a first overtone pulsation. It is further classified as RVb since the average and maximum magnitude varies slowly over several years. The main period also varies over a period of decades. R Sagittae is around 980 light-years (300 parsecs) distant from Earth.〔 It has around 90% the mass of the Sun and an average effective (surface) temperature of around 5000 K.〔 It is around 10,000 times as luminous as the Sun.〔 Variable star observer David Levy recommends that amateur observers monitor it once a week to observe changes in brightness. RV Tauri variables are post-AGB stars, originally similar to the Sun but now in the last stages of their lives. They are crossing the Cepheid instability strip as they lose their outer layers on the way to becoming a planetary nebula. Although their spectra and luminosities resemble supergiants, they are old low mass population II stars. A period-colour-luminosity relationship has been derived from observations of RV Tauri variables in the Large Magellanic Cloud that is closely related to the relationship for type II Cepheid variables. ==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「R Sagittae」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.