Type 1a explosions may result when rocky debris falls onto white dwarf
A few well-aimed asteroids or planets might be all it takes to make a star explode.
A handful of impacts from rocky debris in the atmosphere of a white dwarf, the core of a long dead star, could trigger a powerful explosion known as a type 1a supernova. The proposal, reported online February 1 at arXiv.org, suggests a new way to create this type of supernova, whose origins are still heavily debated.
While the exact mechanisms that might destroy the white dwarf aren’t clear, “the idea isn’t pure speculation,” says Rosanne Di Stefano, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics and lead author on the paper. Astronomers know that rocky material rains down on white dwarfs. The atmospheres of many of these stars are laced with elements such as carbon and silicon that should have quickly sunk deep into the star. Since researchers can still see these atoms, there must be a steady