The Impact of Stellar Surface Magnetoconvection and Oscillations on the Detection of Temperate, Earth-Mass Planets Around Sun-Like Stars. (arXiv:1904.03200v1 [astro-ph.EP])
<a href="http://arxiv.org/find/astro-ph/1/au:+Cegla_H/0/1/0/all/0/1">H. M. Cegla</a>
Detecting and confirming terrestrial planets is incredibly difficult due to
their tiny size and mass relative to Sun-like host stars. However, recent
instrumental advancements are making the detection of Earth-like exoplanets
technologically feasible. For example, Kepler and TESS photometric precision
means we can identify Earth-sized candidates (and PLATO in the future will add
many long-period candidates to the list), while spectrographs such as ESPRESSO
and EXPRES (with an aimed radial velocity precision [RV] near 10 cm/s) mean we
will soon reach the instrumental precision required to confirm Earth-mass
planets in the habitable zones of Sun-like stars. However, many astrophysical
phenomena on the surfaces of these host stars can imprint signatures on the
stellar absorption lines used to detect the Doppler wobble induced by planetary
companions. The result is stellar-induced spurious RV shifts that can mask or
mimic planet signals. This review provides a brief overview of how stellar
surface magnetoconvection and oscillations can impact low-mass planet
confirmation and the best-tested strategies to overcome this astrophysical
noise. These noise reduction strategies originate from a combination of
empirical motivation and a theoretical understanding of the underlying physics.
The most recent predications indicate that stellar oscillations for Sun-like
stars may be averaged out with tailored exposure times, while granulation may
need to be disentangled by inspecting its imprint on the stellar line profile
shapes. Overall, the literature suggests that Earth-analog detection should be
possible, with the correct observing strategy and sufficient data collection.
Detecting and confirming terrestrial planets is incredibly difficult due to
their tiny size and mass relative to Sun-like host stars. However, recent
instrumental advancements are making the detection of Earth-like exoplanets
technologically feasible. For example, Kepler and TESS photometric precision
means we can identify Earth-sized candidates (and PLATO in the future will add
many long-period candidates to the list), while spectrographs such as ESPRESSO
and EXPRES (with an aimed radial velocity precision [RV] near 10 cm/s) mean we
will soon reach the instrumental precision required to confirm Earth-mass
planets in the habitable zones of Sun-like stars. However, many astrophysical
phenomena on the surfaces of these host stars can imprint signatures on the
stellar absorption lines used to detect the Doppler wobble induced by planetary
companions. The result is stellar-induced spurious RV shifts that can mask or
mimic planet signals. This review provides a brief overview of how stellar
surface magnetoconvection and oscillations can impact low-mass planet
confirmation and the best-tested strategies to overcome this astrophysical
noise. These noise reduction strategies originate from a combination of
empirical motivation and a theoretical understanding of the underlying physics.
The most recent predications indicate that stellar oscillations for Sun-like
stars may be averaged out with tailored exposure times, while granulation may
need to be disentangled by inspecting its imprint on the stellar line profile
shapes. Overall, the literature suggests that Earth-analog detection should be
possible, with the correct observing strategy and sufficient data collection.
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