Final answer:
A white dwarf star can be found below and to the left of the main sequence on the Hertzsprung-Russell diagram. They are the surviving cores of low-mass stars at the end of their lives.
Step-by-step explanation:
A white dwarf star can be found below and to the left of the main sequence on the Hertzsprung-Russell diagram. White dwarfs are the surviving cores of low-mass stars at the end of their lives. They have high temperatures but low luminosities, causing them to fall in the lower left corner of the diagram. White dwarfs are formed after the hydrogen-fusion phase, and their position on the diagram is determined by their evolution.