The Iris Nebula (NGC 7023 or Caldwell 4) is a striking reflection nebula located roughly 1,300 to 1,400 light-years from Earth in the northern constellation Cepheus. Unlike emission nebulae that glow from ionized gas, the Iris Nebula shines by scattering starlight off vast clouds of interstellar dust. At its core lies HD 200775, a massive, hot, young star about ten times the mass of the Sun that provides the main illumination for the surrounding material. This glowing dust and gas spans approximately six light-years across, forming petal-like structures that give the nebula its distinctive flower-like appearance in deep-space imagery.
The Iris Nebula (NGC 7023 or Caldwell 4) is a striking reflection nebula located roughly 1,300 to 1,400 light-years from Earth in the northern constellation Cepheus. Unlike emission nebulae that glow from ionized gas, the Iris Nebula shines by scattering starlight off vast clouds of interstellar dust. At its core lies HD 200775, a massive, hot, young star about ten times the mass of the Sun that provides the main illumination for the surrounding material. This glowing dust and gas spans approximately six light-years across, forming petal-like structures that give the nebula its distinctive flower-like appearance in deep-space imagery.