University of Texas astronomer Don Winget and his colleagues use these stellar time machines, which are the crushed cores of once-normal stars like the Sun, to study the birth of the galaxy, the evolution of Sun-like stars, and the process through which these stars disperse chemical elements into space as they die. And with new techniques, they are using white dwarfs to hunt for planets in other star systems. The planetary systems that survive the "deaths" of the stars that become white dwarfs could resemble our own solar system after the Sun evolves into its white-dwarf stage several billion years from now.