We report the discovery of excess K-band radiation from the massive DAZ white dwarf star GD 362. Combining infrared photometric and spectroscopic observations, we show that the excess radiation cannot be explained by a stellar or substellar companion, and is likely to be caused by a debris disk. This would be only the second such system known, discovered 18 years after G29-38, the only single white dwarf currently known to be orbited by circumstellar dust. Both of these systems favor a model with accretion from a surrounding debris disk to explain the metal abundances observed in DAZ white dwarfs. Nevertheless, observations of more DAZs in the mid-infrared are required to test if this model can explain all DAZs.
The Astrophysical Journal Letters
Institute of Physics Publishing, Inc.
Scholarly Commons Citation
Kilic, M., von Hippel, T., & al., e. (2005). Excess Infrared Radiation from the Massive Daz White Dwarf GD 362: A Debris Disk?. The Astrophysical Journal Letters, 632(2). Retrieved from https://commons.erau.edu/publication/275