Below the frame center and just to the right of Alnitak lies the Horsehead Nebula, a dark indentation of dense dust that has perhaps the most recognized nebular shapes on the sky.

• 画面中央偏下，也就是位在参宿一右方的马头星云，由致密的黑暗尘埃组成，应当是天空中最被认可的形状。