Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Physical parameters of the O6.5V+B1V eclipsing binary system LS 1135   ASAS photometric observations of LS 1135, an O-type SB1 binary system with an
orbital period of 2.7 days, show that the system is also eclipsing. This
prompted us to re-examine the spectra used in the previously published
spectroscopic orbit. Our new analysis of the spectra obtained near quadratures,
reveal the presence of faint lines of the secondary component. We present for
the first time a double-lined radial velocity orbit and values of physical
parameters of this binary system. These values were obtained by analyzing ASAS
photometry jointly with the radial velocities of both components performing a
numerical model of this binary based on the Wilson-Devinney method. We obtained
an orbital inclination i ~ 68.5 deg. With this value of the inclination we
deduced masses M1 ~ 30 +/- 1 Mo and M2 ~ 9 +/- 1 Mo; and radii R1 ~ 12 +/- 1 Ro
and R2 ~ 5 +/- 1 Ro for primary and secondary components, respectively. Both
components are well inside their respective Roche lobes. Fixing the Teff of the
primary to the value corresponding to its spectral type (O6.5V), the Teff
obtained for the secondary component corresponds approximately to a spectral
type of B1V. The mass ratio M2/M1 ~ 0.3 is among the lowest known values for
spectroscopic binaries with O-type components.

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The categories of this paper are: gr-qc
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: q-alg
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The categories of this paper are: nlin
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The categories of this paper are: plasm-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: funct-an
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The categories of this paper are: ao-sci
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The categories of this paper are: bayes-an
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The categories of this paper are: math-ph
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The categories of this paper are: solv-int
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The categories of this paper are: cs
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The categories of this paper are: q-bio
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The categories of this paper are: math
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The categories of this paper are: chao-dyn