Heart Nebula
Astrophotography
The Heart Nebula is a large emission nebula located in the constellation Cassiopeia, about 7,500 light‑years from Earth, in the Perseus Arm of our Milky Way. It spans roughly 300 light‑years across. Embedded near its center is the young star cluster Melotte 15 (also known as Collinder 26), whose hot, massive stars (some nearly 50 times the Sun’s mass) emit strong ultraviolet radiation that ionizes the surrounding gas and sculpts dark dust lanes. The nebula’s characteristic red glow comes from ionized hydrogen (Hα emission), along with contributions from ionized oxygen and sulfur in narrowband images. The age of Melotte 15 is very young — around 1.5 million years, indicating that the Heart Nebula is an active star‑forming region.