Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Atomic diffusion in the atmosphere of Feige 86   We have revisited the ultraviolet and optical spectra of the blue horizontal
branch star Feige 86. The new analysis finds the star cooler and more compact
than previously determined. The IUE spectrum of Feige 86 holds numerous
unidentified spectral lines of heavy metals, indicating efficient atomic
diffusion in the atmosphere. Because diffusion plays a key role in the
atmospheres of hot subdwarfs as well, it is indispensable to a better
understanding of subdwarf pulsations and evolution. Feige 86 looks like an
ideal target to confront diffusion theory with observations and test
spectroscopic techniques. Therefore, to advance our general understanding of
diffusion in stellar atmospheres we urge for new ultraviolet spectroscopy of
Feige 86 at the highest possible resolution with HST/STIS.

31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
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The categories of this paper are: dg-ga
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The categories of this paper are: eess
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The categories of this paper are: solv-int
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The categories of this paper are: chao-dyn
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The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
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The categories of this paper are: supr-con
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The categories of this paper are: alg-geom
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The categories of this paper are: comp-gas
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The categories of this paper are: funct-an
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys