Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The First High-Precision Radial Velocity Search for Extra-Solar Planets   In the late 1970s and early 1980s, the introduction of solid-state,
signal-generating detectors and absorption cells to impose wavelength fiducials
directly on the starlight, the errors in stellar radial velocity (RV)
measurements were reduced to the point where Doppler searches for planets
became feasible. In 1980 we began to use a hydrogen fluoride gas cell with the
CFHT coud\'{e} spectrograph and, for 12 years, monitored RVs of some 29
solar-type stars. Since extra-solar planets were expected to resemble Jupiter
in both mass and orbit, we were awarded only three or four two-night observing
runs each year. In 1988 we highlighted a potential planetary companion to
$\gamma$ Cep (K1 IV), in 1993 one to $\beta$ Gem (K0 III), and another to
$\epsilon$ Eri (K2 V) in 1992. The putative planets all resembled Jovian
systems with periods and masses of 2.5 yr and 1.4 $M_{J}$, 1.6 yr and 2.6
$M_{J}$, and 6.9 yr and 0.9 $M_{J}$, respectively. All three were subsequently
confirmed from more extensive data by the Texas group led by Cochran and Hatzes
who derived the currently accepted orbital elements. None of the systems is
simple and some still question $\epsilon$ Eri b.

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The categories of this paper are: stat
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The categories of this paper are: nlin
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The categories of this paper are: gr-qc
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The categories of this paper are: mtrl-th
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The categories of this paper are: atom-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: solv-int
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The categories of this paper are: econ
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The categories of this paper are: math-ph
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The categories of this paper are: eess
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The categories of this paper are: quant-ph
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The categories of this paper are: q-bio
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The categories of this paper are: cmp-lg
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The categories of this paper are: cs
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The categories of this paper are: hep-ph