What percent of stars become planetary nebulas?

A star that is less than eight solar masses expands into a red giant when its core collapses due to depletion of hydrogen and begins to fuse hydrogen in a shell surrounding the core.

The star's outer layers are blasted away from the hot core during this red giant stage, creating a planetary nebular cloud of gas surrounding the core that becomes ionized and brilliantly colored due to radiation from the core.

More than 95 percent of stars are in the less than 8 solar mass range, and in approximately 5 billion years, our Sun will become a planetary nebula.

The massive stars that remain undergo a violent end in the form of a supernova explosion; their outer layers are blasted into space and form nebulae, which are commonly referred to as supernova remnants.

Between 20 and 25 percent of stars eventually form planetary nebulae.