What Happens to Stars around the Size of the Sun?
STAGE 3: The Outer Layers Blow Off
As the star expands,the outer layers blow off at an incredible rate. A star can lose more than half of its mass during this stage.
The gas cloud surrounding the star is called a planetary nebula.
The exposed inner part 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.