English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We report a Spitzer/IRAC search for infrared excesses around white dwarfs,including 14 newly-observed targets and 16 unpublished archived stars. We finda substantial infrared excess around two warm white dwarfs ---J220934.84+122336.5 and WD 0843+516, the latter apparently being the hottestwhite dwarf known to display a close-in dust disk. Extending previous studies,we find that the fraction of white dwarfs with dust disks increases as thestar's temperature increases; for stars cooler than 10,000 K, even the mostheavily polluted ones do not have ~1000 K dust. There is tentative evidencethat the dust disk occurrence is correlated with the volatility of the accretedmaterial. In the Appendix, we modify a previous analysis to show thatPoynting-Robertson drag might play an important role in transferring materialsfrom a dust disk into a white dwarf's atmosphere.

Spitzer Observations of White Dwarfs: the Missing Planetary Debris Around DZ Stars