Glossary term: 紅巨星
Description: 紅巨星是指表面溫度相對較低，但直徑比太陽等主序星大幾十倍甚至上百倍的恆星。相對較低的溫度使恆星表面呈現紅色，而較大的直徑則使恆星的亮度遠超太陽。紅巨星最初是主序星，即類似太陽的恆星，在其內核中通過核聚變將氫燃燒成氦。當這樣一顆恆星的氫燃料耗盡時，它就會開始燃燒氦並合成更重的元素。這時，恆星會膨脹，其表面會在此過程中冷卻下來，隨著體積的增大，恆星會變得更加明亮。太陽將在數十億年後進入紅巨星階段，屆時地球上的生命很可能無法存活。紅巨星的例子有，位於牧夫座的大角星和位於鯨魚座的米拉星。紅巨星的脈動（即恆星反復變大和變小的振盪）並不穩定，在脈動過程中，亮度會發生變化。米拉星就是一個極端的例子，它的亮度可以變化 1000 倍。在天文學家使用的光譜分類中，紅巨星的光譜型大多屬於M型，也有一些屬於K型。紅巨星和所謂的紅超巨星類似，但質量更低。
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Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher The translation of this term and its definition is still awaiting approval
This is an automated transliteration of the simplified Chinese translation of this term
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In Other Languages
- 阿拉伯語: العملاق الأحمر
- 德語: Roter Riese
- 英語: Red Giant
- 法語: Géante rouge
- 義大利語: Gigante rossa
- 日語: 赤色巨星 (external link)
- 簡體中文: 红巨星
Related Media
The red supergiant Betelgeuse
Caption: The image shows Betelgeuse, a red supergiant in the constellation Orion, observed by the Atacama Large Millimeter/submillimeter Array (ALMA). ALMA consists of many antennae spread across a plain in Northern Chile. The observations from all of these receivers is synthesised together by a central computer to form an image. The wide distances between the antennae mean that is can resolve very fine details.
Most stars we observe are just seen as points of light, but Betelgeuse is so large (with a radius about 1,400 times larger than the Sun) and is sufficiently nearby that it is one of the few stars to have been resolved to show it as an extended object.
Betelgeuse is a massive star, more than 14 times the mass of the Sun and is relatively young for a star (less than 14 million years old). However, its high mass led to it having a very hot core which burned through its hydrogen fuel quickly. It has since evolved through many stages and now appears as a red supergiant, it's final stage before exploding as a supernova. When such an explosion will happen is not known for certain, but it could be in around 100,000 years. Such an explosion would be visible from Earth, even during the day.
Credit: ALMA (ESO/NAOJ/NRAO)/E. O’Gorman/P. Kervella
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License: CC-BY-4.0 Creative Commons 姓名標示 4.0 國際 (CC BY 4.0) icons
