What is the life cycle of a star that becomes a white dwarf?
Star forms from a gas cloud ad called nebula.
Due to gravity the cloud collapse to center and forms a proto planet.When temperature increases to 15 million it stars nuclear fusion and become a star..It continue in the main sequence fusing hydrogen to helium..Star remains in balance bt gravity pulling in wards and pressure of fusion pushing outwards..When hydrogen is finished star become red giant.THen outer layers are lost,(Forms planetary nebula). the center shrinks to white dwarf.
picture credit cyberphysics.UK.