A Dusty Disk Around GD 362, a White Dwarf With a Uniquely High Photospheric Metal Abundance
نویسنده
چکیده
Eighteen years after an infrared excess was discovered associated with the white dwarf G29-38, we report ground-based measurements (JHKsKL N ) with mJy-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. Subject headings: circumstellar matter – asteroids – stars, white dwarfs
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