# Reflection nebula

A cloud of dust that shines by reflecting the light of nearby stars, usually bluish.

Dust grains scatter blue light more than red — the same reason the daytime sky is blue — so reflection nebulae look blue in photographs. They don't produce light of their own, so nebula filters don't help; they only dim them.

The Pleiades are wrapped in faint reflection nebulosity (the Merope Nebula is the brightest part); M 78 in Orion is the brightest reflection nebula in the Messier catalog.

**At the eyepiece:** Clean optics and a dark, transparent sky matter: dew or dust on a lens scatters light and can mimic nebulosity around bright stars.

**Examples:** [M78](https://astropilot.space/object/M78.md), [NGC1435](https://astropilot.space/object/NGC1435.md), [NGC1909](https://astropilot.space/object/NGC1909.md), [NGC2261](https://astropilot.space/object/NGC2261.md)

**Related:** [Nebula](https://astropilot.space/glossary/nebula.md), [Emission nebula](https://astropilot.space/glossary/emission-nebula.md), [Transparency](https://astropilot.space/glossary/transparency.md)

From the AstroPilot astronomy glossary: https://astropilot.space/glossary/reflection-nebula