coalsack

Coal.sack

n.（名词）
A dark nebula, one of the nearest to Earth, that appears in the southern Milky Way.
煤袋：最接近地球的黑色星云之一，见于银河系南部
A similar dark nebula in the Northern Hemisphere near the constellation Cygnus.
黑色星云：北半球接近天鹅座的一种类似黑色星云