Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Activity time series of old stars from late F to early K. V. Effect on
  exoplanet detectability with high-precision astrometry   Stellar activity strongly affects and may prevent the detection of Earth-mass
planets in the habitable zone of solar-type stars with radial velocity
technics. Astrometry is in principle less sensitive to stellar activity because
the situation is more favourable: the stellar astrometric signal is expected to
be fainter than the planetary astrometric signal compared to radial velocities.
We quantify the effect of stellar activity on high-precision astrometry when
Earth-mass planets are searched for in the habitable zone around old
main-sequence solar-type stars. We used a very large set of magnetic activity
synthetic time series to characterise the properties of the stellar astrometric
signal. We then studied the detectability of exoplanets based on different
approaches: first based on the theoretical level of false positives derived
from the synthetic time series, and then with blind tests for old main-sequence
F6-K4 stars. The amplitude of the signal can be up to a few times the solar
value depending on the assumptions made for activity level, spectral type, and
spot contrast. The detection rates for 1 MEarth planets are very good, however,
with extremely low false-positive rates in the habitable zone for stars in the
F6-K4 range at 10 pc. The standard false-alarm probability using classical
bootstrapping on the time series strongly overestimates the false-positive
level. This affects the detection rates. We conclude that if technological
challenges can be overcome and very high precision is reached, astrometry is
much more suitable for detecting Earth-mass planets in the habitable zone
around nearby solar-type stars than radial velocity, and detection rates are
much higher for this range of planetary masses and periods when astrometric
techniques are used than with radial velocity techniques.

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The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
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The categories of this paper are: patt-sol
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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: supr-con
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-ex
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The categories of this paper are: funct-an
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The categories of this paper are: math-ph
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The categories of this paper are: nlin
3
The categories of this paper are: physics
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The categories of this paper are: solv-int
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The categories of this paper are: hep-th
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The categories of this paper are: alg-geom
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The categories of this paper are: stat