Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Infrared Photometric Variability of GX13+1 and GX17+2   We present infrared photometry of the Galactic Bulge X-ray binary systems
GX13+1 and GX17+2 obtained in 1997 July and August using OSIRIS on the 1.8m
Perkins Telescope at Lowell Observatory. GX13+1 clearly varies over ~0.6
magnitudes in the K-band. Our light curve suggests a modulation on a timescale
of ~20 days, which is in agreement with previously proposed orbital periods for
the system. The IR counterpart of GX17+2 is also variable in the K-band over
\~0.8 magnitudes on a timescale of days to weeks, extending the variability
first seen by Naylor, Charles, & Longmore (1991). We discuss the implications
our data have for Deutsch et al's (1999) identification of ``star A'' as the
true IR counterpart of GX17+2. The variability observed in our photometry of
the blend of star A and the foreground star NP Ser implies a ~4 magnitude
intrinsic variation in the K-band for GX17+2.

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The categories of this paper are: hep-ph
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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: ao-sci
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: chem-ph
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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: adap-org
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The categories of this paper are: q-alg
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The categories of this paper are: q-bio
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The categories of this paper are: gr-qc
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The categories of this paper are: funct-an
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The categories of this paper are: stat
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The categories of this paper are: chao-dyn