Copyright:
Hunter Wilson
原文:
Why is this galaxy so thin? Many disk galaxies are actually just as thin as NGC 5866, pictured above, but are not seen edge-on from our vantage point. One galaxy that is situated edge-on is our own Milky Way Galaxy. Classified as a lenticular galaxy, NGC 5866 has numerous and complex dust lanes appearing dark and red, while many of the bright stars in the disk give it a more blue underlying hue. The blue disk of young stars can be seen extending past the dust in the extremely thin galactic plane, while the bulge in the disk center appears tinged more orange from the older and redder stars that likely exist there. Although similar in mass to our Milky Way Galaxy, light takes about 60,000 years to cross NGC 5866, about 30 percent less than light takes to cross our own Galaxy. In general, many disk galaxies are very thin because the gas that formed them collided with itself as it rotated about the gravitational center. Galaxy NGC 5866 lies about 50 million light years distant toward the constellation of the Dragon (Draco). Follow APOD on: Facebook, Google Plus, Twitter, or Instagram
中文翻譯:
為什麼這個星系這麼薄？許多盤狀星系與NGC 5866一樣薄，但從我們的視角來看，並不是所有星系都是側面觀察的。我們自己嘅銀河系就正好是其中一個側面觀察的星系。NGC 5866被分類為透鏡星系，擁有數個複雜的灰塵帶，顯得暗紅色，而許多明亮的星星則展現出更藍的底色。年輕星星的藍色盤面可見延伸過灰塵，顯示出非常薄的星系平面，而圓盤中心的凸起部分則因為紅色的老星星而顯得更橙色。雖然NGC 5866的質量與我們的銀河系相似，但光線穿越NGC 5866大約需要60,000年，這大約比光線穿越我們的銀河系少30%。通常來說，許多盤狀星系之所以非常薄，是因為形成它們的氣體在圍繞重力中心旋轉時相互碰撞。NGC 5866大約位於5000萬光年外，朝向龍座（Draco）方向。
#星系 #NGC5866 #銀河 #天文學 #宇宙探索 #科學知識 #太空 #深空觀察 #龍座
來源:NASA每日圖片
