Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Orbital Period of the Be/Neutron Star Binary RX J0812.4-3114   We present the results of Rossi X-ray Timing Explorer observations of the Be
star X-ray binary system RX J0812.4-3114. A light curve obtained with the RXTE
All-Sky Monitor shows that the source is currently in an active state with
outbursts occurring at approximately 80 day intervals. The source underwent a
transition from an inactive state to this regular outburst state early in 1998.
An observation of RX J0812.4-3114 was obtained with the RXTE Proportional
Counter Array close to the time of a predicted maximum in March 1999 and strong
pulsations were detected at a period of 31.88 seconds. This confirms the result
of an earlier PCA observation by Reig & Roche which was serendipitously also
obtained near the predicted maximum flux of the 80 day period and also near the
start of the current active state. We interpret the periodicity in the ASM
light curve as indicating the orbital period of RX J0812.4-3114 with outbursts
occurring around periastron passage.

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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: nucl-ex
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The categories of this paper are: ao-sci
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The categories of this paper are: stat
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The categories of this paper are: chem-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: funct-an
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The categories of this paper are: gr-qc
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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: cond-mat
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The categories of this paper are: adap-org
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The categories of this paper are: hep-lat
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The categories of this paper are: q-fin
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The categories of this paper are: supr-con