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planetary nebula

(PN, PNe)
(gas shell ejected by a red giant)

A planetary nebula (PN or PNe) is ionized gas around an asymptotic giant branch star. The term stems from the era of their first observation since given the observation methods of the time, they resembled planets.

Such nebula are theorized to be matter ejected by pulses in the helium burning of an AGB star (thermal pulse or helium runaway shell).

They are presumed to live on the order of ten thousand years.

Vorontsov-Velyaminov planetary nebula types:

(stars,gas,object type,cloud type)
PNPN G315.4-08.4planetary nebulageneral planetary nebula prefix

Referenced by:
forbidden line
Messier 15 (M15)
MASH Catalog of Planetary Nebulae
Catalogue of Galactic Planetary Nebulae (PK)
planetary nebula luminosity function (PNLF)
protoplanetary nebula (PPN)
Strasbourg-ESO Catalog of Galactic Planetary Nebulae (PNG)