Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Accurate stellar masses in the multiple system T Tau   The goal of this study is to obtain accurate estimates for the individual
masses of the components of the tight binary system T Tau S in order to settle
the ongoing debate on the nature of T Tau Sa, a so-called infrared companion.
We take advantage of the fact that T Tau S belongs to a triple system composed
of two hierarchical orbits to simultaneously analyze the motion of T Tau Sb in
the rest frames of T Tau Sa and T Tau N. With this method, it is possible to
pinpoint the location of the center of mass of T Tau S and, thereby, to
determine individual masses for T Tau Sa and T Tau Sb with no prior assumption
about the mass/flux ratio of the system. This improvement over previous studies
of the system results in much better constraints on orbital parameters. We find
individual masses of 2.73+/-0.31 Msun for T Tau Sa and of 0.61+/-0.17 Msun for
T Tau Sb (in agreement with its early-M spectral type), including the
uncertainty on the distance to the system. These are among the most precise
estimates of the mass of any Pre-Main Sequence star, a remarkable result since
this is the first system in which individual masses of T Tauri stars can be
determined from astrometry only. This model-independent analysis confirms that
T Tau Sa is an intermediate-mass star, presumably a very young Herbig Ae star,
that may possess an almost edge-on disk.

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The categories of this paper are: ao-sci
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The categories of this paper are: adap-org
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The categories of this paper are: plasm-ph
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The categories of this paper are: q-fin
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The categories of this paper are: nlin
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The categories of this paper are: bayes-an
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The categories of this paper are: cmp-lg
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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: chem-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: q-bio
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The categories of this paper are: q-alg
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-lat
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The categories of this paper are: quant-ph