What factor contributes most to the rarity of observing planetary nebulae at any instant?

Answer

Their incredibly short active life compared to stellar evolution

The key factor is their fleeting existence, lasting only about 50,000 years, contrasted with the billions of years stars spend on the main sequence.

What factor contributes most to the rarity of observing planetary nebulae at any instant?

#Videos

JWST Shows Planetary Nebulae Are Way Weirder Than We Thought

raritySpaceastronomystarsnebulaplanetary nebulas