Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A remarkable change of the spectrum of the magnetic Of?p star HD 148937
  reveals evidence of an eccentric, high-mass binary   We report new spectroscopic observations of the magnetic Of?p star HD 148937
obtained since 2015 that differ qualitatively from its extensive historical
record of weak, periodic spectral variations. This remarkable behaviour
represents clear evidence for an unprecedented change in the character of
variability of the star. In this paper we describe the new spectral properties
and compare them to the previous line profiles. Based on measurements of the
radial velocities of the C iii/N iii} emission lines near 4640 \AA\ and the C
iv absorption lines near 5800 \AA, we infer that HD 148937 is likely a
high-mass, double-lined spectroscopic binary. Combining the spectroscopic orbit
with an archival interferometric measurement of the apparent separation of the
equal-brightness components, we tentatively conclude that HD 148937 consists of
two O-type stars with masses of approximately 34 and $49~M_\odot$, orbiting in
an eccentric ($e=0.75$), long-period ($P_{\rm orb}\sim 26$ y) orbit. We discuss
the potential relationship of the binary system to the peculiar properties of
HD 148937, and propose future observations to refine the orbital and stellar
properties.

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The categories of this paper are: bayes-an
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The categories of this paper are: funct-an
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The categories of this paper are: acc-phys
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The categories of this paper are: supr-con
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The categories of this paper are: q-alg
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The categories of this paper are: eess
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The categories of this paper are: cond-mat
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The categories of this paper are: nucl-ex
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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: alg-geom
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The categories of this paper are: ao-sci
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The categories of this paper are: patt-sol
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The categories of this paper are: quant-ph
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The categories of this paper are: math-ph
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The categories of this paper are: solv-int