The Gamma Cygni Nebula, also known as the Sadr Region or IC 1318, is a diffuse emission nebula that can be seen around
Sadr (Gamma Cygni), the star at the center of the
Northern Cross, which marks the heart of
Cygnus, the Swan. Despite the name, the star and the nebula are unrelated. Even though it looks embedded in the nebulosity,
Sadr is approximately 1,800 light years distant, while the nebula is much further away, at 4,900 light years.The Gamma Cygni Nebula is considered an emission nebula because it is ionized by the radiation of the nearby stars and it emits visible light as a result. The visible portion of the H II region stretches over an area more than 100 light years across. The nebula is illuminated by an O9-class star which is visually obscured by interstellar material.
Excerpt from:
Gamma Cygni Nebula (Sadr Region) | Constellation Guide (constellation-guide.com)
Comments