You searched for: “reflection nebulas”
reflection nebula (s) (noun), reflection nebulas; reflection nebulae (pl)
A nebula that shines as the result of the scattering of the light of a star or group of stars nearby: A reflection nebula reflects starlight and looks blue in photographs.

Such scattering is usually caused by dust within the nebula.

This entry is located in the following unit: Astronomy and related astronomical terms (page 21)