planetary nebula
nounEtymology Coined by William Herschel because of their apparent resemblance to the planet Uranus.
1
Astronomy, Natural sciences A nebulosity surrounding a dying red giant, consisting of material expelled by the star.
- Synonyms
- PN
- Derived terms
- preplanetary nebula, protoplanetary nebula, planetary nebula nucleus
- Related terms
- plerion, nova remnant, supernova remnant