Reflection nebula (IC 4592), optical image. IC 4592 is a horsehead-shaped reflection nebula (blue, left); to the right is a smaller reflection nebula IC 4601. Reflection nebulae consist of clouds of fine dust and gas that reflect the light of bright nearby stars. They appear blue as short- wavelength blue light scatters more than red. In the case of IC 4592, the star at the eye of the horse is the source of much of the light. This star is part of Nu Scorpii, a bright star system in the constellation Scorpius, and lies around 450 light years from Earth.