What powers the Heart Nebula? The large emission nebula dubbed IC 1805 looks, in whole, like a human heart. The nebula glows brightly in red light emitted by its most prominent element: hydrogen. The red glow and the larger shape are all created by a small group of stars near the nebula's center. A close up in high dynamic range (HDR) spanning about 30 light years contains many of these stars is shown above. This open cluster of stars contains a few bright stars nearly 50 times the mass of our Sun, many dim stars only a fraction of the mass of our Sun, and an absent microquasar that was expelled millions of years ago. The Heart Nebula is located about 7,500 light years away toward the constellation of Cassiopeia.

心形星云的成因何在?这团整个看起来就像人类的心脏的大发射星云被命名为IC 1805。心型星云明亮的红光闪耀天际并发出最耀眼的氢元素。红光和这样的形状都是由该星云中心附近一小群恒星所致。在封闭的高动态范围(HDR)跨越大约30光年内包含图中所示的这些恒星。这个疏散星团包含一些质量近我们的太阳近50倍的明亮恒星,许多微弱的星星只有太阳质量的一小部分并且缺席的微类星体在百万年前就已经被排除。心型星云距离仙后星座约7500光年。