ExploraTour: A Peek into the Lives of the Stars
What Happens to Low Mass Stars (<8 Solar Masses)?
STAGE 3: Formation of Planetary Nebula
As the star expands, the surface gravity decreases and mass blows off the surface at an incredible rate. A star can lose as much as 50-80% of its mass during this stage. The gas cloud surrounding the star forms a planetary nebula.
Because of this incredible mass loss, gravitational collapse is not able to produce high enough temperatures to fuse the oxygen and carbon in the core to heavier elements.
The exposed core of the star remains as the central star in the planetary nebula. These central stars are the hottest stars known. They are not very luminous because they are extremely small -- about the size of the Earth.