M 27 ：不是彗星
M27: Not a Comet
來源：Francesco Sferlazza, Franco Sgueglia｜發表日期：2024-10-05
當天文學家查爾斯-梅西耶（Charles Messier）在 18 世紀的法國上空尋找彗星時，他勤奮地記錄了一份在望遠鏡探險中遇到的絕對不是彗星的東西的清單。這就是他現在著名的非彗星清單上的第 27 個。事實上， 21 世紀的天文學家會把它認定為行星狀星雲，但它也不是行星，儘管它在小型望遠鏡中看起來像一顆圓形行星。Messier 27 （M 27 ）是氣態發射星雲的一個極好的例子，它是由一顆類似太陽的恆星耗盡了核心中的核燃料而形成的。星雲的形成是由於恆星的外層被排到了太空中，垂死恆星的強烈但不可見的紫外線激發了原子，從而產生了可見的光芒。這個美麗的對稱星際氣體雲被俗稱為啞鈴星雲，直徑超過 2 . 5 光年，距離狐狸座約 1200 光年。這幅令人印象深刻的彩色影像突出顯示了研究得比較透徹的中心區域的細節，以及星雲外暈中較暗、很少成像的特徵。
原文：While hunting for comets in the skies above 18th century France, astronomer Charles Messier diligently kept a list of the things encountered during his telescopic expeditions that were definitely not comets. This is number 27 on his now famous not-a-comet list. In fact, 21st century astronomers would identify it as a planetary nebula, but it's not a planet either, even though it may appear round and planet-like in a small telescope. Messier 27 (M27) is an excellent example of a gaseous emission nebula created as a sun-like star runs out of nuclear fuel in its core. The nebula forms as the star's outer layers are expelled into space, with a visible glow generated by atoms excited by the dying star's intense but invisible ultraviolet light. Known by the popular name of the Dumbbell Nebula, the beautifully symmetric interstellar gas cloud is over 2.5 light-years across and about 1,200 light-years away in the constellation Vulpecula. This impressive color image highlights details within the well-studied central region and fainter, seldom imaged features in the nebula's outer halo.
※ 本文由萌芽機器人自動轉貼自每日一天文圖（Astronomy Picture of the Day，APOD），原文為英文，正體中文是透過 DeepL 翻譯及 OpenCC 進行自動處理，內容僅供參考，若有任何錯誤之處還請見諒！
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