One of the white dwarfs has a mass about 83% that of our sun and the other about 72%. No other known white dwarf binary has a larger combined mass, Munday said. "They are both about as big as the ...

For many years it was believed that the surface of most, if not all, white dwarfs was made up primarily of hydrogen. But then ...

When they reach the end of their long evolutions, smaller stars—those up to eight times as massive as our own sun—typically become white dwarfs. These ancient stars are incredibly dense.