Copyright:Ken Crawford
原文:
One of the brightest galaxies in planet Earth’s sky is similar in size to our Milky Way Galaxy: big, beautiful M81. The grand spiral galaxy can be found toward the northern constellation of the Great Bear (Ursa Major). This superbly detailed image reveals M81’s bright yellow nucleus, blue spiral arms, tell tale pinkish star forming regions, and sweeping cosmic dust lanes with a scale comparable to the Milky Way. Hinting at a disorderly past, a remarkable dust lane actually runs straight through the disk, to the left of the galactic center, contrary to M81’s other prominent spiral features. The errant dust lane may be the lingering result of a close encounter between between M81 and its smaller companion galaxy, M82. Scrutiny of variable stars in M81 has yielded one of the best determined distances for an external galaxy — 11.8 million light-years. M81’s dwarf companion galaxy Holmberg IX can be seen just above the large spiral.
中文翻譯:
其中一個在地球天空中最亮的星系是與我們的銀河系大小相似的美麗M81。呢個壯觀的螺旋星系位於北方的熊座（Ursa Major）。這幅超詳細的圖片展示了M81明亮的黃色核心、藍色的螺旋臂、顯著的粉紅色星際形成區域，同埋廣闊的宇宙塵埃帶，規模與我們的銀河系相當。引人注目的不尋常塵埃帶其實貫穿了星系的盤面，就在銀心左側，與M81其他顯著的螺旋結構形成對比。這條雜亂的塵埃帶可能係M81與其較小的伴星系M82之間密切接觸的結果。對M81的變星進行檢視，得到了外部星系之一的最佳距離測定——1180萬光年。M81的小伴星系Holmberg IX可以在大螺旋星系的正上方看到。
#M81 #銀河系 #星系探索 #宇宙之美 #M82 #HolmbergIX #螺旋星系 #天文 #觀星 #星際形成
來源:NASA每日圖片
