Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A superburst from 4U 1254-690   We report the detection with the BeppoSAX Wide Field Cameras of a superburst
from 4U 1254-690. The superburst is preceded by a normal type-I X-ray burst,
has a decay time that is the longest of all eight superbursts detected so far
and a peak luminosity that is the lowest. Like for the other seven superbursts,
the origin is a well-known type-I X-ray burster with a persistent luminosity
level close to one tenth of the Eddington limit. Based on WFC data of all
persistently bright X-ray bursters, the average rate of superbursts is
0.51+/-0.25 per year per persistently bright X-ray burster. Some systems may
have higher superburst rates. For all superbursters, we present evidence for a
pure helium layer which is burnt in an unstable as well as a stable manner.

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The categories of this paper are: mtrl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: solv-int
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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: alg-geom
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The categories of this paper are: supr-con
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The categories of this paper are: comp-gas
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The categories of this paper are: gr-qc
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The categories of this paper are: q-bio
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-lat
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The categories of this paper are: ao-sci
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The categories of this paper are: eess
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The categories of this paper are: math
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The categories of this paper are: hep-th