How long does the visible phase of a planetary nebula typically last on astronomical timescales?

Answer

10,000 to 50,000 years

The entire visible phase of a planetary nebula is relatively brief, lasting perhaps only ten thousand to fifty thousand years before the gas dissipates too much to be observable.

How long does the visible phase of a planetary nebula typically last on astronomical timescales?
astronomystarsnebulaeVisibilityplanetary nebulae