Astronomy Picture of the Day

Explanation: Almost unknown to casual observers in the northern hemisphere, the southern sky contains two diffuse wonders known as the Magellanic Clouds. The Magellanic Clouds are small irregular galaxies orbiting our own larger Milky Way spiral galaxy. The Small Magellanic Cloud (SMC), pictured here, is about 250,000 light years away and contains a preponderance of young, hot, blue stars indicating it has undergone a recent period of star formation. There is evidence that the SMC is not gravitationally bound to the LMC.

南半球的天空，有二個北半球不經心觀星者幾乎不知、名為麥哲星系的瀰漫天體。 分類為不規則小星系的麥哲倫星系，繞行我們的大螺旋星系（銀河系）。 上圖呈現的是距離地球約250,000光年遠的小麥哲倫星系，其內有大量的年輕熾熱泛藍恆星，這顯示它最近發生過恆星形成活動。 目前的證據顯示，小麥哲倫星系與大麥哲倫星系之間並無重力束縛。