Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The CARMENES search for exoplanets around M dwarfs - The enigmatic
  planetary system GJ 4276: One eccentric planet or two planets in a 2:1
  resonance?   We report the detection of a Neptune-mass exoplanet around the M4.0 dwarf GJ
4276 (G 232-070) based on radial velocity (RV) observations obtained with the
CARMENES spectrograph. The RV variations of GJ 4276 are best explained by the
presence of a planetary companion that has a minimum mass of $m_{\rm b}\sin i
\approx 16\, M_\oplus$ on a $P_{\rm b}=13.35$ day orbit. The analysis of the
activity indicators and spectral diagnostics exclude stellar induced RV
perturbations and prove the planetary interpretation of the RV signal. We show
that a circular single-planet solution can be excluded by means of a likelihood
ratio test. Instead, we find that the RV variations can be explained either by
an eccentric orbit or interpreted as a pair of planets on circular orbits near
a period ratio of 2:1. Although the eccentric single-planet solution is
slightly preferred, our statistical analysis indicates that none of these two
scenarios can be rejected with high confidence using the RV time series
obtained so far. Based on the eccentric interpretation, we find that GJ 4276 b
is the most eccentric ($e_{\rm b} = 0.37$) exoplanet around an M dwarf with
such a short orbital period known today.

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The categories of this paper are: hep-lat
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The categories of this paper are: quant-ph
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The categories of this paper are: supr-con
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The categories of this paper are: hep-ex
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The categories of this paper are: comp-gas
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The categories of this paper are: econ
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The categories of this paper are: math
12
The categories of this paper are: nucl-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: nlin
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-fin
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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: chem-ph
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The categories of this paper are: stat