IC 348 and NGC 1333, optical image. The reflection nebula IC 348 is at upper left, another reflection nebula at centre right. This type of nebula does not produce its own light but reflects the light from the stars within it. Reflection nebulae appear blue due to blue light being scattered more than red light. In between these two nebulae is a red emission nebula. Radiation from hot new stars ionises the hydrogen in the nebula's dust and gas clouds, making it glow red. The silhouettes over the emission nebula are black filaments of dense dust clouds known as dark nebulae. These nebulae are found near the constellation Perseus.