mariah 2009-3-24 14:31
Great Carina Nebula - 船底座大星雲
Eta and Keyhole in the Carina Nebula
[img]http://i13.tinypic.com/42xxbfr.jpg[/img]
影像版權與提供: Brad Moore
[color=navy]Explanation: [/color]
[color=dimgray]South is toward the top in this colorful close-up view of the Great Carina Nebula (NGC 3372), famous star-forming region of the southern sky. Covering an area surrounding the dusty Keyhole Nebula (NGC 3324) near picture center, the image spans about 40 light-years within the larger Carina Nebula at an estimated distance of 7,500 light-years. Like the more northerly Orion Nebula, the bright Carina Nebula is easily visible to the naked-eye. But the dramatic colors in this telescopic picture are mapped colors, based on three exposures through narrow filters each intended to record the light emitted by specific atoms in the gaseous nebula. Sulfur is shown in blue, hydrogen in green and oxygen in red hues. The Carina Nebula is home to young, extremely massive stars, including the still enigmatic variable Eta Carinae, a star with well over 100 times the mass of the Sun. Highlighted by diffraction spikes, Eta is just above and right (east) of the Keyhole. [/color]
[color=navy]說明:[/color]
[color=dimgray]船底座大星雲 (NGC 3372)是南天著名的恆星形成區，上面這幅該星雲的彩色特寫影像頂端是南方，影像涵蓋了鎖孔星雲 (NGC 3324)周圍的天區。船底座星雲的推算距離為是7,500光年，所以這幅影像呈現了船底座星雲約四十光年的區域。就像北天的獵戶座星雲一樣，用肉眼就能輕易看到明亮的船底座星雲。不過這幅動人彩色望遠鏡影像的顏色是轉置色彩，製作影像的根據是三張透過某些特定窄波段濾鏡所拍攝的照片，每一個單張記錄了這個團雲內特定原子所輻射的光；其中硫以藍色代表，氫為綠色而氧則為紅色。船底座星雲是極大質量年輕恆星的家園，範例之一為神祕難解的變星海山二星，該星的質量為太陽的百倍以上。海山二星位在鎖孔星雲的右上方，是那顆被繞射芒給突顯出來的天體。
名詞對照：船底座大星雲 (Great Carina Nebula)、鎖孔星雲 (Keyhole Nebula)、海山二星 (Eta Carinae)。[/color]
[size=2]資料來源: Scientific American
Department of Physics, NCKU[/size][color=white][size=1]
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