Copyright:Rogelio Bernal
Andreo
原文:
Rising at the start of a northern summer’s night, these three bright stars form the familiar asterism known as the Summer Triangle. Altair, Deneb, and Vega are the alpha stars of their respective constellations, Aquila, Cygnus, and Lyra, nestled near the Milky Way. Close in apparent brightness the three do look similar in these telescopic portraits, but all have their own stellar stories. Their similar appearance hides the fact that the Summer Triangle stars actually span a large range in intrinsic luminosity and distance. A main sequence dwarf star, Altair is some 10 times brighter than the Sun and 17 light-years away, while Vega, also a hydrogen-fusing dwarf, is around 30 times brighter than the Sun and lies 25 light-years away. Supergiant Deneb, at about 54,000 times the solar luminosity, lies some 1,400 light-years distant. Of course, with a whitish blue hue, the stars of the Summer Triangle are all hotter than the Sun.
中文翻譯:
在北半球的夏季之夜升起的這三顆亮星，形成了著名的星群——夏季三角形。Altair、Deneb 和 Vega 分別是其所屬星座 Aquila、Cygnus 和 Lyra 的α星，恰好坐落在銀河系附近。雖然在望遠鏡下這三顆星星在明亮度上相似，但它們的恆星故事卻各具特色。它們的外觀雖然相似，但實際上，夏季三角形的星星在內在亮度和距離上差異巨大。Altair 是一顆主序矮星，亮度約為太陽的10倍，距離我們17光年；而 Vega 也是一顆氫聚變的矮星，亮度約為太陽的30倍，距離25光年。相比之下，超巨星 Deneb 的亮度約為54,000倍太陽，距離則達到1,400光年。當然，這三顆夏季三角形的星星都是暖白色的藍色星，所有的溫度都高於太陽。
#夏季三角形 #Altair #Deneb #Vega #天文學 #星空 #銀河系 #恆星故事 #北半球 #星座 #科學探索
來源:NASA每日圖片
