Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Quiescent Optical and Infrared Counterpart to EXO 0748-676 = UY Vol   We present optical and infrared photometry of the low-mass X-ray binary EXO
0748-676 in quiescence for the first time in 24 years since it became X-ray
active in 1985. We find the counterpart at average magnitudes of R=22.4 and
J=21.3. We monitored the source approximately nightly through 2008 November to
2009 January. During this time there was considerable night-to-night optical
variability but no long term trends were apparent. The night-to-night
variability reveals a periodicity of P=0.159331+/-0.000012d, consistent with
the X-ray orbital period to within 0.01%. This indicates that the quiescent
optical modulation is indeed orbital in nature rather than a superhump.
Interestingly, the modulation remains single-peaked with a deep minimum
coincident with the times of X-ray eclipse, and there is no indication of a
double-peaked ellipsoidal modulation. This indicates that even in `quiescence'
emission from the accretion disk and/or X-ray heated inner face of the
companion star dominate the optical emission, and implies that obtaining an
accurate dynamical mass estimate in quiescence will be challenging.

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The categories of this paper are: alg-geom
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The categories of this paper are: q-alg
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: dg-ga
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The categories of this paper are: q-fin
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The categories of this paper are: bayes-an
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The categories of this paper are: stat
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The categories of this paper are: math
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The categories of this paper are: nlin
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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: physics
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The categories of this paper are: cs
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The categories of this paper are: nucl-th
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The categories of this paper are: math-ph