Stellar Afterlife

Sirius, the brightest star in the night sky, has a "dead" companion -- a white dwarf star known as Sirius B (shown next to Earth, in scale, in this artist's concept). A white dwarf is the dead core of a once-normal star. The core could no longer produce energy, so the star cast off its outer layers, leaving the core behind. Although it produces no nuclear reactions, the white dwarf continues to shine because it is extremely hot. Sirius B is one of the heaviest white dwarfs yet discovered. It is as massive as the Sun, yet no bigger than Earth. Its surface gravity is about 350,000 times that of Earth, so a person who weighs 150 pounds on Earth would top the scales at more than 50 million pounds at the surface of Sirius B. [ESA/NASA]