Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The carbon monoxide-rich interstellar comet 2I/Borisov   Interstellar comets offer direct samples of volatiles from distant
protoplanetary disks. 2I/Borisov is the first notably active interstellar comet
discovered in our solar system[1]. Comets are condensed samples of the gas,
ice, and dust that were in a star's protoplanetary disk during the formation of
its planets and inform our understanding on how chemical compositions and
abundances vary with distance from the central star. Their orbital migration
moves volatiles[2], organic material, and prebiotic chemicals in their host
system[3]. In our solar system, hundreds of comets have been observed remotely,
and a few have been studied up close by space missions[4]. However, knowledge
of extrasolar comets has been limited to what could be gleaned from distant,
unresolved observations of cometary regions around other stars, with only one
detection of carbon monoxide[5]. Here we report that the coma of 2I/Borisov
contains significantly more CO than H2O gas, with abundances of at least 173%,
more than three times higher than previously measured for any comet in the
inner (<2.5 au) solar system[4]. Our ultraviolet observations of 2I/Borisov
provide the first glimpse into the ice content and chemical composition of the
protoplanetary disk of another star that is substantially different from our
own.

15
The categories of this paper are: nucl-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
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The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
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The categories of this paper are: hep-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: chem-ph
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The categories of this paper are: stat
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The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
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The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
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The categories of this paper are: cs
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The categories of this paper are: acc-phys