Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Orbital Evolution and Proper Motion of PSR J2051-0827   We have carried out high-precision timing observations of the eclipsing
binary PSR J2051-0827 in the 3.3 years since its discovery. These data indicate
that the orbital period is decreasing at a rate of dPb/dt = (-11+-1)X10^-12. If
secular, this orbital period derivative implies a decay time for the orbit of
only 25 Myr which is much shorter than the expected timescale for ablation of
the companion. We have also measured the proper motion of the pulsar to be 5+-3
mas/yr. Assuming the pulsar is at the dispersion-measure distance this implies
a very slow transverse velocity vt=(30+-20) km/s. This combination of low
velocity and short orbital period argue against formation of the system in the
standard manner and we discuss the implications for its evolutionary history.

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The categories of this paper are: ao-sci
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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-th
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The categories of this paper are: stat
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The categories of this paper are: supr-con
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The categories of this paper are: q-bio
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The categories of this paper are: chem-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: acc-phys
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The categories of this paper are: math
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The categories of this paper are: adap-org
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The categories of this paper are: mtrl-th
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The categories of this paper are: cmp-lg
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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: patt-sol