In astronomical terms,planetary nebulae
A) exist around their central white dwarf stars for millions of years before slowly spreading into space.
B) are relatively long-lived because they form when the original stars form and remain as slowly rotating shells for the whole of the star's lifetime of several billion years.
C) are very short-lived,with lifetimes of about 50,000 years.
D) are very long-lived objects,having been in existence since the Big Bang at the beginning of the universe.

Question

Quizplus · Accepted Answer

Planetary nebulae are short-lived objects, with lifetimes of about 50,000 years. They form when low-mass stars (like our Sun) reach the end of their lives and shed their outer layers of gas, creating a beautiful glowing shell known as a planetary nebula. Over time, the gas in the nebula dissipates, and the central star cools down and becomes a white dwarf. But the planetary nebula itself only lasts for a relatively brief period of time.

In Astronomical Terms,planetary Nebulae