Pollution of single white dwarfs by accretion of many small asteroids

Abstract

Extrapolating from the solar system's asteroid belt, we propose that externally contaminated white dwarfs without an infrared excess may be experiencing continuous accretion of gas-phase material that is ultimately derived from the tidal destruction of multiple small asteroids. If this scenario is correct, then observations of metal-polluted white dwarfs may lead to determination of the bulk elemental compositions of ensembles of extrasolar minor planets. © 2008. The American Astronomical Society. All rights reserved.