Cambridge, Mass. -- U.S. astronomers say they've discovered a number of previously unobserved double-star systems, some of them heading toward a spectacularly explosive fate.
The newly identified binary star systems all consist of two white dwarf stars that are on a collision course with each other, SPACE.com reported Wednesday.
A white dwarf is the hot, incredibly dense dead core that remains after a sun-like star blows off its outer layers as it dies.
"These are weird systems -- objects the size of the Earth orbiting each other at a distance less than the radius of the sun," says astronomer Warren Brown of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.