What stellar spectral types are usually responsible for powering an emission nebula?

Answer

O or B spectral types

The intense energy required to cause ionization comes from the hottest, brightest stars, which are generally classified as spectral types O or B.

What stellar spectral types are usually responsible for powering an emission nebula?

#Videos

How Does Ionization Cause Emission Nebulae To Glow? - YouTube

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