Q&A: Normal Stars, White Dwarf Stars, and Star Clusters

Q:
Please educate me !! On page 3 of your web site http://chandra.harvard.edu/xray_sources/white_dwarfs3.html you refer to "degenerate" electron pressure in white dwarfs which keeps the star from collapsing in on itself. Surely there would not be any electrons left in a star after the Wolf-Rayet stage? The star having blow them off when forming a planetary nebula.

A:
The electrical forces between positively charged ions and negatively charged electrons tends to keep the average charge of matter close to zero, so if electrons flow off a star, an electric field is set up that pulls the protons off along with them. What’s left behind is also a mixture of electrons and protons, which is what a plasma is.