Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Detection of magnetic dipole lines of Fe XII in the ultraviolet spectrum
  of the dwarf star Epsilon Eri   We report observations of the dwarf star Epsilon Eri (K2 V) made with the
Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope
(HST). The high sensitivity of the STIS instrument has allowed us to detect the
magnetic dipole transitions of Fe XII at 1242.00A and 1349.38A for the first
time in a star other than the Sun. The width of the stronger line at 1242.00A
has also been measured; such measurements are not possible for the permitted
lines of Fe XII in the extreme ultraviolet. To within the accurcy of the
measurements, the N V and the Fe XII lines occur at their rest wavelengths.
Electron densities and line widths have been measured from other transition
region lines. Together, these can be used to investigate the non-thermal energy
flux in the lower and upper transition region, which is useful in constraining
possible heating processes. The Fe XII lines are also present in archival STIS
spectra of other G/K-type dwarfs.

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The categories of this paper are: eess
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The categories of this paper are: nucl-th
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The categories of this paper are: plasm-ph
2
The categories of this paper are: math
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The categories of this paper are: dg-ga
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The categories of this paper are: adap-org
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-fin
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The categories of this paper are: math-ph
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The categories of this paper are: hep-th
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The categories of this paper are: econ
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The categories of this paper are: q-bio
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The categories of this paper are: chao-dyn
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The categories of this paper are: cs
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The categories of this paper are: mtrl-th
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The categories of this paper are: supr-con