The impact of unresolved magnetic spots on high precision radial velocity measurements. (arXiv:2007.12193v1 [astro-ph.EP])
<a href="http://arxiv.org/find/astro-ph/1/au:+Lisogorskyi_M/0/1/0/all/0/1">Maksym Lisogorskyi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Saikia_S/0/1/0/all/0/1">Susdeshna Boro Saikia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jeffers_S/0/1/0/all/0/1">Sandra V. Jeffers</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jones_H/0/1/0/all/0/1">Hugh R. A. Jones</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Morin_J/0/1/0/all/0/1">Julien Morin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mengel_M/0/1/0/all/0/1">Matthew Mengel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Reiners_A/0/1/0/all/0/1">Ansgar Reiners</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vidotto_A/0/1/0/all/0/1">Aline A. Vidotto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Petit_P/0/1/0/all/0/1">Pascal Petit</a>

The Doppler method of exoplanet detection has been extremely successful, but
suffers from contaminating noise from stellar activity. In this work a model of
a rotating star with a magnetic field based on the geometry of the K2 star
Epsilon Eridani is presented and used to estimate its effect on simulated
radial velocity measurements. A number of different distributions of unresolved
magnetic spots were simulated on top of the observed large-scale magnetic maps
obtained from eight years of spectropolarimetric observations. The radial
velocity signals due to the magnetic spots have amplitudes of up to 10 m
s$^{-1}$, high enough to prevent the detection of planets under 20 Earth masses
in temperate zones of solar type stars. We show that the radial velocity
depends heavily on spot distribution. Our results emphasize that understanding
stellar magnetic activity and spot distribution is crucial for detection of
Earth analogues.

The Doppler method of exoplanet detection has been extremely successful, but
suffers from contaminating noise from stellar activity. In this work a model of
a rotating star with a magnetic field based on the geometry of the K2 star
Epsilon Eridani is presented and used to estimate its effect on simulated
radial velocity measurements. A number of different distributions of unresolved
magnetic spots were simulated on top of the observed large-scale magnetic maps
obtained from eight years of spectropolarimetric observations. The radial
velocity signals due to the magnetic spots have amplitudes of up to 10 m
s$^{-1}$, high enough to prevent the detection of planets under 20 Earth masses
in temperate zones of solar type stars. We show that the radial velocity
depends heavily on spot distribution. Our results emphasize that understanding
stellar magnetic activity and spot distribution is crucial for detection of
Earth analogues.

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