Deep-sky object class · e.g. The Orion Nebula (M42)
Emission Nebula
A cloud of interstellar gas that glows with its own light, ionised by the ultraviolet radiation of nearby hot stars so that it re-emits in characteristic lines — most famously the red of hydrogen. Emission nebulae mark regions of active star formation and include the great HII regions of the Galaxy.
Highlights
- ›Gas glowing red where hot young stars ionise it
Examples & related concepts
Across the encyclopedia
Knowledge connections
- Associated withDeep-Sky Object
- Associated withOrion Nebula
- Associated withLagoon Nebula
- Associated withHII Region
- Associated withStar-Forming Regions
- Associated withHII Region
- Associated withReflection Nebula
- Associated withNarrowband Imaging
Sources
The primary and reference sources this topic draws on.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.