| 翻訳と辞書 |
| Lambda Ursae Majoris ： ウィキペディア英語版 |
Lambda Ursae Majoris
Lambda Ursae Majoris (Lambda UMa, λ Ursae Majoris, λ UMa) is a star in the northern circumpolar constellation of Ursa Major. It has the proper names Tania Borealis (former ''Tania borealis''〔Piazzi, G., ''The Palermo Catalogue'', Palermo, 1814.〕).
This star has an apparent visual magnitude of +3.45,〔 making it one of the brighter members of the constellation. The distance to this star has been measured directly using the parallax technique, which yields a value of roughly with a 4% margin of error. The stellar classification of Lambda Ursae Majoris is A2 IV,〔 with the luminosity class of 'IV' indicating that, after 410 million years〔 on the main sequence, this star is in the process of evolving into a giant star as the supply of hydrogen at its core becomes exhausted. Compared to the Sun it has 240% of the mass and 230% of the Sun's radius, but is radiating 37 times as much luminosity.〔 This energy is being emitted from the star's outer atmosphere at an effective temperature of 9,280 K,〔 giving it the characteristic white-hot glow of an A-type star.〔
==Name and etymology==
*The traditional name ''Tania (share with μ UMa) comes from the Arabic phrase "the Second Spring (of the Gazelle)".〔(Richard Hinckley Allen :Star Names — Their Lore and Meaning - Ursa Major, the Greater Bear )〕 The term ''Borealis'' meaning "the north side" in Latin.
*In Chinese, (), meaning ''Three Steps'', refers to an asterism consisting of λ Ursae Majoris, ι Ursae Majoris, κ Ursae Majoris, μ Ursae Majoris, ν Ursae Majoris and ξ Ursae Majoris. Consequently, λ Ursae Majoris itself is known as (, (英語:the Third Star of Three Steps)) and (, (英語:Star of First Middle Step)).〔 ((Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 21 日 )〕
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「Lambda Ursae Majoris」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.
|
|