A Dusty Disk around GD 362, a White Dwarf with a Uniquely High Photospheric Metal Abundance

Eighteen years after an infrared excess was discovered associated with the white dwarf G29-38, we report ground-based measurements (JHK_sKL^'N^') with millijansky-level sensitivity of GD 362 that show it to be a second single white dwarf with an infrared excess. As a first approximation, the excess around GD 362, which amounts to ~3% of the total stellar luminosity, can be explained by emission from a passive, flat, opaque dust disk that lies within the Roche radius of the white dwarf. The dust may have been produced by the tidal disruption of a large parent body such as an asteroid. Accretion from this circumstellar disk could account for the remarkably high abundance of metals in the star's photosphere.