Planetary nebula
A planetary nebula was a type of emission nebula created by matter expelled from a star reaching the end of its life.

The crew of  surveyed a planetary nebula in 2151, at which time they detected a Vulcan survey ship apparently shadowing their activities. This happened three weeks before Enterprise encountered the  Ti'Mur. ()

Examples
 Jonisian Nebula
 M2-9

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Celestial objects