What is a white dwarf?
Q: What is a white dwarf?
A: A white dwarf is a compact star whose matter has been squashed together by gravitation and had its electrons taken off.
Q: How does the mass of a white dwarf compare to the Sun?
A: The mass of a white dwarf is similar to that of the Sun, but its volume is similar to that of the Earth.
Q: What type of stars become white dwarfs?
A: White dwarfs are the final evolutionary state of all stars whose mass is not high enough to become a neutron star. Over 97% of the stars in the Milky Way will become white dwarf stars.
Q: How does a red giant form?
A: After the hydrogen–fusing lifetime of a main-sequence star ends, it will expand to form a red giant which fuses helium to carbon and oxygen in its core. If it does not have enough mass to fuse carbon, inactive carbon and oxygen will build up at its center.
Q: What happens after shedding its outer layers to form a planetary nebula?
A: After shedding its outer layers to form a planetary nebula, what remains behind is the core which becomes the white dwarf.
Q: Does material in a white dwarf undergo fusion reactions?
A: No, material in a white dwarf no longer undergoes fusion reactions so there is no source of energy for it and it can't be supported by heat against gravitational collapse.
Q: How does our Sun become a White Dwarf?
A: Our Sun will become a White Dwarf when it has run out fuel near the end of its life; first going through red giant stage then losing most gas until what's left contracts into young White Dwarf
