Unexpectedly strong effect of supergranulation on the detectability of Earth twins orbiting Sun-like stars with radial velocities

Abstract

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.

Accepted in A&A Letters

References in corpus (8)

• Search for exoplanets with the radial-velocity technique: quantitative diagnostics of stellar activity
• Radial-Velocity Fitting Challenge. II. First results of the analysis of the data set
• Filtering solar-like oscillations for exoplanet detection in radial velocity observations
• Habitability of known exoplanetary systems based on measured stellar properties
• Radial Velocity Fitting Challenge. I. Simulating the data set including realistic stellar radial-velocity signals
• Activity time series of old stars from late F to early K. I. Simulating radial velocity, astrometry, photometry, and chromospheric emission
• A study of periodograms standardized using training data sets and application to exoplanet detection
• Semi-analytical formulas for the Hertzsprung-Russell Diagram

Cited by in corpus (22)

• The EXPRES Stellar Signals Project II. State of the Field in Disentangling Photospheric Velocities
• Astrophysical Insights into Radial Velocity Jitter from an Analysis of 600 Planet-search Stars
• Observing the Sun as a star: Design and early results from the NEID solar feed
• Target Prioritization and Observing Strategies for the NEID Earth Twin Survey
• Characterisation of stellar activity of M dwarfs. I. Long-timescale variability in a large sample and detection of new cycles
• Doppler Constraints on Planetary Companions to Nearby Sun-like Stars: An Archival Radial Velocity Survey of Southern Targets for Proposed NASA Direct Imaging Missions
• On the radial distribution of giant exoplanets at Solar System scales
• Radial-velocity variations due to meridional flows in the Sun and solar-type stars: impact on exoplanet detectability
• Testing the Spectroscopic Extraction of Suppression of Convective Blueshift
• $\text{GRASS}$: Distinguishing Planet-induced Doppler Signatures from Granulation with a Synthetic Spectra Generator
• Modelling stellar activity with Gaussian process regression networks
• Unsigned magnetic flux proxy from solar optical intensity spectra
• Activity time series of old stars from late F to early K. V. Effect on exoplanet detectability with high-precision astrometry
• A new estimation of astrometric exoplanet detection limits in the habitable zone around nearby stars
• Activity time series of old stars from late F to early K VI. Exoplanet mass characterisation and detectability in radial velocity
• Multi-Mask Least-Squares Deconvolution: Extracting RVs using tailored masks
• Solar Photospheric Spectrum Microvariability I. Theoretical searches for proxies of radial-velocity jittering
• The Lowell Observatory Solar Telescope: A fiber feed into the EXtreme PREcision Spectrometer
• Using Doppler Imaging to model stellar activity and search for planets around Sun-like stars
• Semi-supervised standardized detection of extrasolar planets
• Astrometric exoplanet detection survives solar-like stellar contamination
• Spectral Ratio Analysis: probing of a new suite of stellar activity indicators as a tool for astrophysical noise mitigation