Believe it or not, I really poured my heart into this one — the Heart Nebula. Nearly 5 hours of total exposure, then about twice that long spent processing and reprocessing. I’ll forever be learning how to do this.
About the Heart Nebula
The Heart Nebula (also known as IC 1805, Sharpless 2-190, or the Running Dog Nebula) is a large emission nebula in the constellation Cassiopeia, roughly 7,500 light-years away in the Perseus Arm of the Milky Way.
It gets its name from its distinctive heart-shaped outline formed by glowing ionized hydrogen gas and dark dust lanes. The brightest western portion is catalogued separately as NGC 896. At the center sits the young open star cluster Melotte 15 (also called IC 1805 or Collinder 26). This cluster contains several massive, hot stars (some nearly 50 times the mass of the Sun) only about 1.5 million years old. Their intense ultraviolet radiation and stellar winds ionize the surrounding gas, making the nebula glow, and carve out intricate dust pillars.
Key facts:
Type: Emission nebula (primarily hydrogen, with oxygen and sulfur contributing blues and oranges in narrowband images)
Apparent size: About 150 × 150 arcminutes (roughly 2.5 degrees across — several times the diameter of the full Moon)
Physical size: Radius around 150–165 light-years (diameter roughly 300+ light-years)
Discovered: William Herschel in 1787; later identified as a radio source (Westerhout 4 / W4)
It forms part of the larger Heart and Soul complex with the nearby Soul Nebula (IC 1848 / W5). The region is an active stellar nursery where new stars continue to form. It’s a popular target for astrophotographers because of its striking shape and rich structure, though it has relatively low surface brightness and benefits from long exposures under dark skies.