Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The G\"ottingen Solar Radial Velocity Project: Sub-m/s Doppler precision
  from FTS observations of the Sun as a star   Radial velocity observations of stars are entering the sub-m/s domain
revealing fundamental barriers for Doppler precision experiments. Observations
of the Sun as a star can easily overcome the m/s photon limit but face other
obstacles. We introduce the G\"ottingen Solar Radial Velocity Project with the
goal to obtain high precision (cm/s) radial velocity measurements of the Sun as
a star with a Fourier Transform Spectrograph. In this first paper, we present
the project and first results. The photon limit of our 2 min observations is at
the 2 cm/s level but currently limited by strong instrumental systematics. A
drift of a few m/s per h is visible in all observing days probably caused by
vignetting of the solar disk in our fiber coupled setup, and imperfections of
our guiding system adds further offsets in our data. Binning the data into 30
min groups shows m/s stability after correcting for a daily and linear
instrumental trend. Our results show the potential of Sun-as-a-star radial
velocity measurements that can possibly be achieved after a substantial upgrade
of our spectrograph coupling strategy. Sun-as-a-star observations can provide
crucial empirical information about the radial velocity signal of convective
motion and stellar activity, and on the wavelength dependence of radial
velocity signals caused by stellar line profile variations.

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The categories of this paper are: chem-ph
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The categories of this paper are: adap-org
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The categories of this paper are: ao-sci
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The categories of this paper are: cmp-lg
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The categories of this paper are: physics
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The categories of this paper are: q-fin
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The categories of this paper are: econ
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The categories of this paper are: math
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The categories of this paper are: cs
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The categories of this paper are: cond-mat
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The categories of this paper are: nlin
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The categories of this paper are: q-bio
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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: acc-phys