Unexpectedly strong effect of supergranulation on the detectability of Earth twins orbiting Sun-like stars with radial velocities. (arXiv:1904.09089v1 [astro-ph.EP])

Unexpectedly strong effect of supergranulation on the detectability of Earth twins orbiting Sun-like stars with radial velocities. (arXiv:1904.09089v1 [astro-ph.EP])
<a href="http://arxiv.org/find/astro-ph/1/au:+Meunier_N/0/1/0/all/0/1">N. Meunier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lagrange_A/0/1/0/all/0/1">A.-M. Lagrange</a>

Magnetic activity and surface flows at different scales pertub radial
velocity measurements. This affects the detectability of low-mass exoplanets.
In these flows, the effect of supergranulation is not as well characterized as
the other flows, and we wish to estimate its effect on the detection of
Earth-like planets in the habitable zone of Sun-like stars. We produced time
series of radial velocities due to oscillations, granulation, and
supergranulation, and estimated the detection limit for a G2 star and a period
of 300 days. We also studied in detail the behavior of the power when the
signal of a 1 Mearth planet was superposed on the signal from the stellar
flows. We find that the detection rate does not reach 100% except for the
supergranulation level we assume, which is still optimistic, and for an
excellent sampling. We conclude that with current knowledge, it is a very
challenging task to find Earth twins around Sun-like stars with our current
capabilities.

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