"It's fascinating," says astronomer Michael Jura of the University of California, Los Angeles, who was not part of the discovery team. "They've actually caught in the act the process of some asteroid breaking into pieces, being disrupted by the white dwarf host star."
Indeed, the star itself is the asteroids' enemy. Its gravity has torn them asunder, and its light is vaporizing their rock. The asteroids are so close to the star that they revolve in just 4.5 to 4.9 hours; Vanderburg estimates they are roughly the size of Ceres, the largest asteroid between the orbits of Mars and Jupiter...."