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arXiv · 0704.1170

Externally-polluted white dwarfs with dust disks

M. Jura·J. Farihi·B. Zuckerman
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Abstract

We report Spitzer Space Telescope photometry of eleven externally-polluted white dwarfs. Of the nine stars for which we have IRAC photometry, we find that GD 40, GD 133 and PG 1015+161 each has an infrared excess that can be understood as arising from a flat, opaque, dusty disk. GD 56 also has an infrared excess characteristic of circumstellar dust, but a flat-disk model cannot reproduce the data unless there are grains as warm as 1700 K and perhaps not even then. Our data support the previous suggestion that the metals in the atmosphere of GD 40 are the result of accretion of a tidally-disrupted asteroid with a chondritic composition.

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M. Jura, J. Farihi, B. Zuckerman. 2007-04-10. Externally-polluted white dwarfs with dust disks. https://doi.org/10.1086/518767

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